Hi all trying to rewire my 593TA as loom wires were all over the place & falling apart , i have a new loom but the colours are not strictly matching up plus the wiring diagram does not say what wires go where on the rectifier the new loom wires are red, green ,purple light greenish & the rectifier is solid state , the bike is positive earth , i need to know what wires to to the +on the rec & the only other bit i can see says ac? Thanks
3TALAD
Hi,
While I'll answer your direct question, you should know you're doing absolutely the wrong thing rewiring a 66-year-old bike with any sort of copy of a 66-year-old wiring loom, it's silly because modern electrics are so much simpler thanks to advances in those 66 years - to paraphrase the punchline of an old "Irish" joke, if you want to get to a bike with reliable modern electrics, you don't start from 66-year-old principles.
Basic understanding
That the wiring diagram shows both a battery and an alternator means the bike has two electrical power sources; however, because a battery produces Direct Current (DC) while an alternator produces Alternating Current (AC), a battery and an alternator cannot be connected together directly - the rectifier in between rectifies AC to DC to keep the battery charged and allows the alternator to power other "consumers" - ignition, lighting - without its output conflicting with the battery's output.
You have posted "the bike is positive earth". If you look harder at the wiring diagram, there's a line labelled "RED" between "BATTERY" "+" and an 'earth' symbol. There's also a line from "RECTIFIER" to an 'earth' symbol. So why wouldn't the loom "red" wire by the rectifier connect to the rectifier's positive terminal? Particularly as you can use your multimeter set to Ohms to verify the two Red wire terminals are connected through the loom?
![Image]()
... while not all are labelled exactly the same, the positive terminal is always the one at 90 degrees to the other three.
Then more looking at the wiring diagram, note the line marked "PURPLE" between "RECTIFIER" and "LIGHTING AND IGNITION SWITCH". As another switch terminal is connected to "BATTERY" "-", more thinking doesn't suggest the Purple wire should be connected to the rectifier's corresponding negative terminal, especially if the rectifier is marked "-" by the terminal diametrically opposite the positive terminal?
Next note the wiring diagram shows a line marked "LIGHT GREEN" between "ALTERNATOR" and "RECTIFIER"; so at least one of your loom's "light greenish" wires doesn't correspond to this? Now you know the alternator generates AC, if one of the rectifier terminals has "~" on the rectifier under the terminal, that's the symbol for AC. The rectifier's other AC terminal is the one diametrically opposite.
Finally here, ime it's most-likely the other loom "light greenish" wire should be connected to the rectifier's other AC terminal; however, you should verify this by checking the loom connections for the alternator stator wires and, if necessary, again using your multimeter's Ohms function between the loom's rectifier and stator connections.
BUT (and it's a J-Lo) ... imho, you are digging a hole for yourself using a copy of a '59 loom and a plain rectifier:-
. Same as your bike's old loom, your bike's new loom doesn't have automatic alternator Volts and Amps regulation - absent that, you cannot fit a more-powerful alternator, a more powerful headlamp or any LED lighting to your bike. Your earliest post says you're customising your bike for a "desert sled" look - you're really retaining the nacelle to mount the (ancient as the original wiring?) PRS8 combined lighting and ignition switch, is required for what passed for alternator output "regulation" when your bike was built?
. As a basic, you can substitute a modern combined regulator/rectifier for the bike's existing plain rectifier - with a reg./rec. alternator output regulation will be automatic, you can fit more-powerful alternator, more powerful headlamp, LED lighting as desired.
However, be clear, no reg./rec. will fit in the space currently occupied by the plain rectifier; reg./rec., you'll have to select a new space for it, you'll need wires, terminals, crimping tools, insulators to connect the reg./rec. from that space to the bike's loom.
. Even without a new alternator with increased output, connecting the rectifier to the battery through the lighting/ignition switch was crap for reliability, Lucas dropped the idea for '66 when the last British bikes previously regulating alternator output with rider-operated switches converted to automatic regulation.
Ordinarily, I'd suggest making the bike's new loom is a much better idea, particularly for a custom bike - wire in the correct diagram colours, terminals, crimping tools, insulators, etc. are all available from at least three British retailers; the total cost will be about the same as an off-the-shelf loom but you'll have tools and spares when you've finished. Making a new loom is possible even starting with little electrical knowledge; however, you have to be prepared to think logically and, to paraphrase the old Donald Rumsfeld quote, you have to ask lots of questions before you do something so there are fewer "unknown unknowns".
Hth.
Regards,
It does, the problem is the manual you should be using - Triumph Instruction Manual No.4 - wasn't written for people attempting something without the most basic understanding of what they're trying to achieve - in your case, rewiring a 66-year-old OAP without the most basic understanding of simple electrics.
While I'll answer your direct question, you should know you're doing absolutely the wrong thing rewiring a 66-year-old bike with any sort of copy of a 66-year-old wiring loom, it's silly because modern electrics are so much simpler thanks to advances in those 66 years - to paraphrase the punchline of an old "Irish" joke, if you want to get to a bike with reliable modern electrics, you don't start from 66-year-old principles.
Basic understanding
That the wiring diagram shows both a battery and an alternator means the bike has two electrical power sources; however, because a battery produces Direct Current (DC) while an alternator produces Alternating Current (AC), a battery and an alternator cannot be connected together directly - the rectifier in between rectifies AC to DC to keep the battery charged and allows the alternator to power other "consumers" - ignition, lighting - without its output conflicting with the battery's output.
You have posted "the bike is positive earth". If you look harder at the wiring diagram, there's a line labelled "RED" between "BATTERY" "+" and an 'earth' symbol. There's also a line from "RECTIFIER" to an 'earth' symbol. So why wouldn't the loom "red" wire by the rectifier connect to the rectifier's positive terminal? Particularly as you can use your multimeter set to Ohms to verify the two Red wire terminals are connected through the loom?
... while not all are labelled exactly the same, the positive terminal is always the one at 90 degrees to the other three.
Then more looking at the wiring diagram, note the line marked "PURPLE" between "RECTIFIER" and "LIGHTING AND IGNITION SWITCH". As another switch terminal is connected to "BATTERY" "-", more thinking doesn't suggest the Purple wire should be connected to the rectifier's corresponding negative terminal, especially if the rectifier is marked "-" by the terminal diametrically opposite the positive terminal?
Next note the wiring diagram shows a line marked "LIGHT GREEN" between "ALTERNATOR" and "RECTIFIER"; so at least one of your loom's "light greenish" wires doesn't correspond to this? Now you know the alternator generates AC, if one of the rectifier terminals has "~" on the rectifier under the terminal, that's the symbol for AC. The rectifier's other AC terminal is the one diametrically opposite.
Finally here, ime it's most-likely the other loom "light greenish" wire should be connected to the rectifier's other AC terminal; however, you should verify this by checking the loom connections for the alternator stator wires and, if necessary, again using your multimeter's Ohms function between the loom's rectifier and stator connections.
BUT (and it's a J-Lo) ... imho, you are digging a hole for yourself using a copy of a '59 loom and a plain rectifier:-
. Same as your bike's old loom, your bike's new loom doesn't have automatic alternator Volts and Amps regulation - absent that, you cannot fit a more-powerful alternator, a more powerful headlamp or any LED lighting to your bike. Your earliest post says you're customising your bike for a "desert sled" look - you're really retaining the nacelle to mount the (ancient as the original wiring?) PRS8 combined lighting and ignition switch, is required for what passed for alternator output "regulation" when your bike was built?
. As a basic, you can substitute a modern combined regulator/rectifier for the bike's existing plain rectifier - with a reg./rec. alternator output regulation will be automatic, you can fit more-powerful alternator, more powerful headlamp, LED lighting as desired.
However, be clear, no reg./rec. will fit in the space currently occupied by the plain rectifier; reg./rec., you'll have to select a new space for it, you'll need wires, terminals, crimping tools, insulators to connect the reg./rec. from that space to the bike's loom.. Even without a new alternator with increased output, connecting the rectifier to the battery through the lighting/ignition switch was crap for reliability,
Lucas dropped the idea for '66 when the last British bikes previously regulating alternator output with rider-operated switches converted to automatic regulation.Ordinarily, I'd suggest making the bike's new loom is a much better idea, particularly for a custom bike - wire in the correct diagram colours, terminals, crimping tools, insulators, etc. are all available from at least three British retailers; the total cost will be about the same as an off-the-shelf loom but you'll have tools and spares when you've finished.
Making a new loom is possible even starting with little electrical knowledge; however, you have to be prepared to think logically and, to paraphrase the old Donald Rumsfeld quote, you have to ask lots of questions before you do something so there are fewer "unknown unknowns". Hth.
Regards,
That is really helpful & thanks for all the info, i am not keeping the nacelle or PRS8 switch as the switch was in bits & that is not the look i was going for so i want to have a separate ignition & light switch , i have managed to get a spark at both plugs with connecting the dark green & light green from the alternator to the AC on rectifier & connecting the purple & negative battery terminal to the + & - that left me a red wire which i am assuming is an earth for the rectifier, also the brown /blue & the white wire together seems to make the connection & i have put a rocker switch on that for now i have no idea if this is right but i was happy to at least get a spark but whether it charges etc is another story when i have figured out that problem then the other one will be how to wire the lighting etc
Hi,
However, imho stop there simply joining wires, no fuses (another thing wrong with a '59 loom, any pre-'66 Britbike loom), you risk damage with a short-circuit. Imho, think about switches and the switched functions you want, as they'll govern wires routings, that'll govern wires numbers and lengths.
Reasons are: parts are available easily off the shelf; if you need help later on, anyone trying to help doesn't have to figure out your personal logic before they can help. You won't always be able to use Britbike parts; when you don't, pay more than the cheapest on Ebay for ones from a bike with a wiring diagram online so, if you need help, you can show the wiring diagram.
Separate switches, where are you going to mount 'em? Lighting switch is relatively easy as long as you're happy using one of the standard Lucas headlamp shells and a Lucas lever ("toggle") switch.
Otoh, some of the places Triumph mounted the ignition key switch as standard, it's like Meriden had a committee (that met every Friday lunchtime in the pub?) to devise the most inconvenient place. Absent a desire to mount the ignition switch next to the speedo., the next-most 'convenient' standard Triumph mounting is in the drive-side headlamp mounting "ear" but that assumes you want the corresponding fork shrouds between the yokes?
If a key ignition switch is intended, bear in mind some Triumphs have a combined ignition and lighting switch as standard, with a switch incorporated in a handlebar cluster just to turn the headlamp on/off.
... a new alternator would be high up my shopping list ...
).
Otoh, plain White is the Lucas colour code for "switched power" - between the 'master switch' and components that should be 'on' when the master switch is 'on'. So whether or not your chosen 'master switch' has a key, it should be between Brown/Blue and White wires.
For later, a component with a White "switched power" wire could be another switch, for a component or components that aren't always 'on' when the master switch is 'on' but shouldn't work when the master switch is 'off'; e.g. a stop lamp switch.
If you consider my earlier advice to use off-the-shelf Britbike components, the lever lighting switch Wassell supplies as "Lucas" has three positions - off, pilot (say connected to one or more white LED at the front of the bike) and headlamp; the switch also turns off anything connected to the "pilot" terminal when the "headlamp" position is selected and vv.
Fuses
Only mentioned briefly so far, the absolute minimum should be one fuse in the one-and-only wire actually connected to the battery 'earth' terminal (battery positive at present). I advise common automotive 'blade' fuse/holder and, when you select the holder, consider a type that can have one or more holders clipped to it, to store one or more spare fuses on the bike.
Just as a matter of interest, are you considering fitting indicators?
Hth.
Regards,
However, imho stop there simply joining wires, no fuses (another thing wrong with a '59 loom, any pre-'66 Britbike loom), you risk damage with a short-circuit. Imho, think about switches and the switched functions you want, as they'll govern wires routings, that'll govern wires numbers and lengths.
Digressing slightly, when selecting electrical parts - e.g. switches - I advise, as a principle, try to use standard late Britbike parts, or at least parts with functions that owners of late Britbikes will recognise. Similar with wire colours, I advise standard late Lucas colours for the same connections/purposes.
Reasons are: parts are available easily off the shelf; if you need help later on, anyone trying to help doesn't have to figure out your personal logic before they can help. You won't always be able to use Britbike parts; when you don't, pay more than the cheapest on Ebay for ones from a bike with a wiring diagram online so, if you need help, you can show the wiring diagram.
Ignition switch - there is a school of thought that says tickling a carb. and kickstarting are so alien to most motorcyclists, they'll be alien to any would-be thief, so something like a rocker or lever switch is good enough as an on/off 'master' switch, no key to be lost. However, ime that doesn't allow for the mean human spirit, that would leave the switch turned on to flatten the battery ...
Separate switches, where are you going to mount 'em? Lighting switch is relatively easy as long as you're happy using one of the standard Lucas headlamp shells and a Lucas lever ("toggle") switch.
Otoh, some of the places Triumph mounted the ignition key switch as standard, it's like Meriden had a committee (that met every Friday lunchtime in the pub?) to devise the most inconvenient place. Absent a desire to mount the ignition switch next to the speedo., the next-most 'convenient' standard Triumph mounting is in the drive-side headlamp mounting "ear" but that assumes you want the corresponding fork shrouds between the yokes?
If a key ignition switch is intended, bear in mind some Triumphs have a combined ignition and lighting switch as standard, with a switch incorporated in a handlebar cluster just to turn the headlamp on/off.
Mmmm ... the stator wire colours (along with a "mid green"-colour wire?) says this is probably the original alternator, it's certainly very old. So whether or not it "charges", it's output even when new was barely adequate. Today ...
... a new alternator would be high up my shopping list ...When wiring your bike, I strongly advise against assuming electrical components 'earthed' to random metal bits of bike have a long-term-reliable electrical conductor to a battery terminal (battery positive for 'positive earth'). That the loom includes a specific Red wire for rectifier positive says, even in '59, while the original rectifier could 'earth' through its mounting, Lucas didn't consider that reliable, supplied an insulated wire that was connected between the rectifier mounting and other Red wires in the loom to the battery positive terminal. By the time Triumph produced the last "dry frame" bike in 1976, its standard Lucas loom contained a network of Red wires that connected almost every electrical component to battery positive (in contrast, whoever designed the '71 OIF loom for Triumph and BSA excluded a number of improvements that'd been made by '70, that weren't ever reincorporated in later OIF looms
).Brown/Blue is the Lucas colour code for "unswitched power" on bikes, that is the wire between (in 'positive earth') battery negative and the 'master switch' that isolates all other electrical components from the battery.
Otoh, plain White is the Lucas colour code for "switched power" - between the 'master switch' and components that should be 'on' when the master switch is 'on'. So whether or not your chosen 'master switch' has a key, it should be between Brown/Blue and White wires.
For later, a component with a White "switched power" wire could be another switch, for a component or components that aren't always 'on' when the master switch is 'on' but shouldn't work when the master switch is 'off'; e.g. a stop lamp switch.
Desire for "parking lights" absent (or the lighting switch becomes another 'master switch'), the lighting switch can be supplied by the ignition switch. While you might want lights on in daylight, I advise against both using the headlamp and having the rear lamp on, especially if you have to stick with the feeble original alternator for any length of time.
If you consider my earlier advice to use off-the-shelf Britbike components, the lever lighting switch Wassell supplies as "Lucas" has three positions - off, pilot (say connected to one or more white LED at the front of the bike) and headlamp; the switch also turns off anything connected to the "pilot" terminal when the "headlamp" position is selected and vv.
Fuses
Only mentioned briefly so far, the absolute minimum should be one fuse in the one-and-only wire actually connected to the battery 'earth' terminal (battery positive at present). I advise common automotive 'blade' fuse/holder and, when you select the holder, consider a type that can have one or more holders clipped to it, to store one or more spare fuses on the bike.
Just as a matter of interest, are you considering fitting indicators?
Hth.
Regards,
Really helpful advice that , i was thinking of a simple toggle switch for the lights & again a simple key ignition mounted on a side panel with the 2 holes ( Tiger 90) ones & the horn switch and dipped beam same as original mounted on handlebars , no indicators were going to be fitted ( not at this stage anyway ) am i right in thinking by what you have said that Brown/Blue & White for on /off ignition . your not near North Yorkshire by any chance are you !!!!!
Hi,
![]()
... note the switch and the lock/keys are separate parts.
Btw, if you want to look at Lucas parts online, enter "lucas " and the part number into your browser's Search bar, the browser'll return images and links to several dealers with stock. However, be aware, while long-time Triumph dealer TMS has a website, their stock isn't linked online; always worth checking their prices against that of dealers with stock online, I often find TMS is the cheapest for the same parts.
put it. It was only a key switch from '66; previously, the ignition switch had been a rotary switch. Problem with the key switch in the sidepanel is riders knocked it with their legs, broke off the key's serrated part in the lock, why Meriden moved it to the headlamp mounting "ear" from '68.
However, if you go ahead and use the sidepanel with two holes, consider using the second hole for the Lucas 34289 rotary lighting switch:-
![]()
. Requires two tiny threaded holes in the left handlebar to mount the switch, restricting your choice of handlebars; forget about drilling holes in any old 'bar, requires some sophisticated machine tools and a jig to drill the holes accurately.
. The horn/dip "same as original" is a rabbit hole with a dead-end - the horn 'works' when that button 'earths' to the handlebar, so:-
.. the horn itself is special, must be insulated from its mounting, can't 'earth' through it mounting as most modern horns do;
.. to get the electrons from the button or the handlebar reliably , so the horn actually sounds reliably when the button's pressed, requires some extra work;
.. if you decide later you do want indicators, you'll scrap all the work as horn buttons in switch clusters work conventionally.
Reason to think about it now is, if any particularly LED indicators look attractive, 'negative earth' are far more common than 'positive earth', easier to change to 'negative earth' now than when the bike's built.
Your bike can't continue to use a plain rectifier.
Cheap and reliable reg./rec. - reg./rec. plus connector or if you want to pay the extra for stock in GB.
Hth.
Regards,
That'll be Lucas 30608:-
... note the switch and the lock/keys are separate parts.
Btw, if you want to look at Lucas parts online, enter "lucas " and the part number into your browser's Search bar, the browser'll return images and links to several dealers with stock. However, be aware, while long-time Triumph dealer TMS has a website, their stock isn't linked online; always worth checking their prices against that of dealers with stock online, I often find TMS is the cheapest for the same parts.
One of the inconvenient places the aforementiond committee
put it. It was only a key switch from '66; previously, the ignition switch had been a rotary switch. Problem with the key switch in the sidepanel is riders knocked it with their legs, broke off the key's serrated part in the lock, why Meriden moved it to the headlamp mounting "ear" from '68.Ime, no; better control of lighting needed than just a single on/off switch:-
... is part number 31788 or 35710.
However, if you go ahead and use the sidepanel with two holes, consider using the second hole for the Lucas 34289 rotary lighting switch:-
Two snags to be aware of with that horn/dipswitch:-
. Requires two tiny threaded holes in the left handlebar to mount the switch, restricting your choice of handlebars; forget about drilling holes in any old 'bar, requires some sophisticated machine tools and a jig to drill the holes accurately.
. The horn/dip "same as original" is a rabbit hole with a dead-end - the horn 'works' when that button 'earths' to the handlebar, so:-
.. the horn itself is special, must be insulated from its mounting, can't 'earth' through it mounting as most modern horns do;
.. to get the electrons from the button or the handlebar reliably , so the horn actually sounds reliably when the button's pressed, requires some extra work;
.. if you decide later you do want indicators, you'll scrap all the work as horn buttons in switch clusters work conventionally.
... i.e. your "key ignition" Lucas 30608 switch above would have the Brown/Blue wire from the battery connected to one of the "U"-shaped terminals on its rear, White wire connected to the other "U"-shaped terminal.
Ime, I advise a rethink. A 3TA is slow, many road users don't have a clue what hand signals are plus, when you want to indicate right for any reason, the necessary hand is controlling the twistgrip. My T150 doesn't have indicators, simple stuff like indicating to overtake is a pita. I appreciate you won't be overtaking on the motorway on a 3TA but there are plenty of other situations. Take a look on, say, the M&P website or Search "motorcycle indicators" on Fleabay, plenty of small unobtrusive ones.
Reason to think about it now is, if any particularly LED indicators look attractive, 'negative earth' are far more common than 'positive earth', easier to change to 'negative earth' now than when the bike's built.
Uh-uh, Highlands.
With respect, why?
Your bike can't continue to use a plain rectifier.Cheap and reliable reg./rec. - reg./rec. plus connector or if you want to pay the extra for stock in GB.
Hth.
Regards,
Apart from the excellent advice that Stuart has provided I can add my twopenn’orth from the mistakes I made when I did mine.
Assuming you are going to make a new loom as recommended.
first job is to make a wiring diagram, I used power point to do mine but paper and pencil is fine as long as you have a big rubber. You will need this in a couple of years down the line.
I used traditional bullet connectors but some of the ones I bought were rubbish and keep coming apart. I have been changing to the Japanese style that click together. Much better.
I used my own colours for the wires. Big mistake try to keep to the Triumph colours. Try and match the colours to the tails on the electrical components. Not always possible.
Fit an earth wire to all components or at least near to them, try not to rely on the frame for the earth.
I failed to put the wiring in for indicators. Even if you do not plan to put indicators on, put the wires in. It will be a PIA if you change your mind later.
Plan and dry fit all your components. Don’t assume you can make them fit. There is some rumours that putting the alternator and points wires together can cause problems. I have on my BSA and have had no problems.
if you have connections open to the weather eg points and alternator wires, use water proof connections.
Definitely change to LEDs.
I changed to -ve earth. Don’t need to bother as you can get all the electrical components for the existing +ve earth even LEDs not sure about the price (Unless you want to).
finally I used self amalgamating tape to cover the loom. Great stuff but not if you get petrol on it. Also you need more protection as the loom goes around the head stock.
John
Stuart I would be interested in your take on these suggestions. Every day is a school day.
Assuming you are going to make a new loom as recommended.
first job is to make a wiring diagram, I used power point to do mine but paper and pencil is fine as long as you have a big rubber. You will need this in a couple of years down the line.
I used traditional bullet connectors but some of the ones I bought were rubbish and keep coming apart. I have been changing to the Japanese style that click together. Much better.
I used my own colours for the wires. Big mistake try to keep to the Triumph colours. Try and match the colours to the tails on the electrical components. Not always possible.
Fit an earth wire to all components or at least near to them, try not to rely on the frame for the earth.
I failed to put the wiring in for indicators. Even if you do not plan to put indicators on, put the wires in. It will be a PIA if you change your mind later.
Plan and dry fit all your components. Don’t assume you can make them fit. There is some rumours that putting the alternator and points wires together can cause problems. I have on my BSA and have had no problems.
if you have connections open to the weather eg points and alternator wires, use water proof connections.
Definitely change to LEDs.
I changed to -ve earth. Don’t need to bother as you can get all the electrical components for the existing +ve earth even LEDs not sure about the price (Unless you want to).
finally I used self amalgamating tape to cover the loom. Great stuff but not if you get petrol on it. Also you need more protection as the loom goes around the head stock.
John
Stuart I would be interested in your take on these suggestions. Every day is a school day.
Hi John,
cheap one I bought recently:-
![]()
... only crimps with two opposite sides.
Hex. crimp tools still available, just not cheap ...
Nowadays, "things like handlebar switch clusters" come with "Japanese bullets" (although usually without the insulators). Two things to watch with 'em:-
. They come in two sizes - 3.6 mm. (bullet OD, aka "3.5 mm.") and 3.9 mm. (aka "4 mm."), having the correct ID socket is wise but only 3.9 mm. are available in GB. Only place I know 3.6 mm./3.5 mm. are available retail in sensible quantities is Cycle Terminal in the US, but the guy doesn't appear to like dealing outside the US - I had to get a friend in the US to buy what I wanted, him send 'em to me.
. As the CT webpage shows, four wires is the largest number that can be connected in common, whereas it's up to eight with 3/16" OD "Lucas bullets", that I certainly use when creating any given bike's 'earth' network.
Have to say though, when I first added relays for the headlamp, I did similar; when I discovered the full extent of the Lucas/British Standard wire colour codes, how much easier was that ... obviously correct wire colours then available off the shelf ...
Recently discovered low-cost screened wire at Polevolt that has virtually the same conductor cross-section area as the 9/0.30 I use usually (so "Lucas bullets" for 9/0.30 wire should fit well). Have bought a couple of metres of the screened to try on the T100's Boyer-Bransden Mk.3.
makes a near-waterproof seal. Almost completely waterproof if the socket's filled with Vaseline (petroleum jelly for non-GB readers) before the bullet and insulator are fitted.
Only 'wrapping' I do is short lengths of Split Convoluted Conduit/"Slit" Convoluted Tubing over the wires exposed between, say, the front of the tank and the headlamp shell - the Split/"Slit" is lengthways along the Conduit/Tubing so the wires don't have to be disconnected to fit/remove the Conduit/Tubing. Adding or removing wires is quick, no additional protection required around the frame headstock.
Hth?
Regards,
Depends on the crimping tool? The one I bought all the way back in the early 1980's does a full hex. crimp,
cheap one I bought recently:-
... only crimps with two opposite sides.
Hex. crimp tools still available, just not cheap ...
I started with hex. crimp "Lucas bullets" because things like handlebar switch clusters came with 'em as standard then; changing 'em to something else then finding the part didn't work and having to change 'em back again before the part could be returned was a pain.
Nowadays, "things like handlebar switch clusters" come with "Japanese bullets" (although usually without the insulators
). Two things to watch with 'em:-. They come in two sizes - 3.6 mm. (bullet OD, aka "3.5 mm.") and 3.9 mm. (aka "4 mm."), having the correct ID socket is wise but only 3.9 mm. are available in GB. Only place I know 3.6 mm./3.5 mm. are available retail in sensible quantities is Cycle Terminal in the US, but the guy doesn't appear to like dealing outside the US - I had to get a friend in the US to buy what I wanted, him send 'em to me.
. As the CT webpage shows, four wires is the largest number that can be connected in common, whereas it's up to eight with 3/16" OD "Lucas bullets", that I certainly use when creating any given bike's 'earth' network.
Have to say though, when I first added relays for the headlamp, I did similar; when I discovered the full extent of the Lucas/British Standard wire colour codes, how much easier was that ... obviously correct wire colours then available off the shelf ... +1.
Mmmm ... some of the pattern electrical parts makers are rather cavalier about correct wire colours ...
+1.
+1.
Alternator wires close to wires between EI electronics Boxes and trigger units are where interference problems are more likely. Electricity and magnetism are linked inextricably; if a wire's conducting, it'll have a magnetic field around it, magnetic strength dependent on current being conducted; magnetism induces electron movement in adjacent wires (e.g. how an alternator works); the relatively-high current between alternator stator and rectifier or reg./rec. could induce a small current in parallel EI trigger wires; EI trigger wires carry a low current anyway, EI electronics work by measuring the varying current and Voltages generated by the trigger unit to calculate spark advance/retard; EI electronics can't tell the difference between current/Volts from the trigger unit and current/Volts induced by another power source; the risk is incorrect spark advance/retard for the rpm.
Recently discovered low-cost screened wire at Polevolt that has virtually the same conductor cross-section area as the 9/0.30 I use usually (so "Lucas bullets" for 9/0.30 wire should fit well
). Have bought a couple of metres of the screened to try on the T100's Boyer-Bransden Mk.3.If using "Japanese bullets" and sockets, if both a bullet and a socket have the correct insulators, the insulators seal in/on each other when the bullet's pushed into the socket,
makes a near-waterproof seal. Almost completely waterproof if the socket's filled with Vaseline (petroleum jelly for non-GB readers) before the bullet and insulator are fitted.Mmmm ... only one I'd question is the headlamp. If you're absolutely 100% certain you'll never, ever ride even at dusk (because you stayed longer than intended at a friend's?), cheap LED headlamp 'bulb' will do. Otoh, if you don't want bike use defined by the headlamp, good quartz-halogen is much cheaper than good LED.
Mmmm ... the exception is complete LED headlamps; I don't know of any positive-earth ones?
I've never wrapped any loom I've built. First one, I'd built it on the bike using releasable reusable zipties to fasten the wires to frame tubes (more than the two VWP lengths are available on Ebay). I did intend to wrap that loom but wanted to test my handiwork first. Then the longer it went without problems, plus lack of the access problems as on the original wrapped loom ...
Only 'wrapping' I do is short lengths of Split Convoluted Conduit/"Slit" Convoluted Tubing over the wires exposed between, say, the front of the tank and the headlamp shell - the Split/"Slit" is lengthways along the Conduit/Tubing so the wires don't have to be disconnected to fit/remove the Conduit/Tubing.
Adding or removing wires is quick, no additional protection required around the frame headstock.Hth?
Regards,
With the help of our resident Faraday I designed this basic diagram for my 59 5Ta. It was converted to 12v and had EI so the diagram reflected this. I also added fuses
It may help, it may not
![Image]()
It may help, it may not
Hi Mick,
Even when I started my first rewire in late 1982, wire had metric cross-sectional areas - e.g. common 14-strand wire, each strand is 0.30 mm. OD, adding up to 1 sq.mm. total conductor cross-section.
However, old Lucas wire has 32SWG strands = each strand is only 0.274 mm. OD, adds up to less than 1 sq.mm., crimping most modern bullet terminals doesn't reduce their ID enough to make the required tight interference-fit on the slightly-smaller conductor.
That said, I have encountered a problem with bullets particularly on modern 32/0.20 "thinwall" wire. Supposed to be 1 sq.mm. cross-section too but the one time I was forced to use it (bike owner bought it), I had a devil of a job trying to get the bullets to stick. 🤬 Only had the problem the once as I've refused to use it since ... Otoh, I always use 28/0.30 thinwall for wires common to several circuits, never a problem with that and bullets.
Hth.
Regards,
Crimping a "Lucas bullet" reduces its ID by a certain amount, that should end up a tight interference-fit on the conductor.
Even when I started my first rewire in late 1982, wire had metric cross-sectional areas - e.g. common 14-strand wire, each strand is 0.30 mm. OD, adding up to 1 sq.mm. total conductor cross-section.
However, old Lucas wire has 32SWG strands = each strand is only 0.274 mm. OD, adds up to less than 1 sq.mm., crimping most modern bullet terminals doesn't reduce their ID enough to make the required tight interference-fit on the slightly-smaller conductor.
That said, I have encountered a problem with bullets particularly on modern 32/0.20 "thinwall" wire. Supposed to be 1 sq.mm. cross-section too but the one time I was forced to use it (bike owner bought it), I had a devil of a job trying to get the bullets to stick. 🤬 Only had the problem the once as I've refused to use it since ...
Otoh, I always use 28/0.30 thinwall for wires common to several circuits, never a problem with that and bullets. +1. I've used Vehicle Wiring Products since they were Merv Plastics, have also used the aforementioned Autosparks for decades.
Hth.
Regards,
Mick
I had the same problem. The pack I bought from AES were ok but a top up from eBay were a rubbish fit.
my cheap crimping tool was ok most of the time I did resort to soldering some of the connections and always tinned the bear wires before crimping. Some crimped bullets distorted but they did not come apart then.
I used a little kitchen blowtorch to solder the bullets, a normal soldering iron cannot get the whole bullet hot enough for the solder to flow without melting the wire insulation.
John
I had the same problem. The pack I bought from AES were ok but a top up from eBay were a rubbish fit.
my cheap crimping tool was ok most of the time I did resort to soldering some of the connections and always tinned the bear wires before crimping. Some crimped bullets distorted but they did not come apart then.
I used a little kitchen blowtorch to solder the bullets, a normal soldering iron cannot get the whole bullet hot enough for the solder to flow without melting the wire insulation.
John
I have both kinds of bullet crimper, the cheap one works pretty well but the crimp looks ugly. Hex crimps are not very tolerant of wire size. Once the hex tool is closed you can’t just go a little bit tighter.
What I do if the wire is undersized and the next size down ID bullet won’t fit, is to “fill out” the bullet ID with some extra strands cut from a stripped piece of the same wire. I can then get a really good looking and reliable crimp.
I sometimes solder stuff too, as long as the wire is not subject to flexing near the connector and you don’t allow the solder to wick too much up the wire they can be reliable, I have stuff I did 40 years ago on bikes and speaker systems that’s still working fine. Some grease to keep the moisture out is always good.
Has to be said, some of the snap connectors you can buy really don’t work very well, don’t grip the bullets securely. Some don’t actually “snap”. Squeezing to tighten them doesn’t always work either.
What I do if the wire is undersized and the next size down ID bullet won’t fit, is to “fill out” the bullet ID with some extra strands cut from a stripped piece of the same wire. I can then get a really good looking and reliable crimp.
I sometimes solder stuff too, as long as the wire is not subject to flexing near the connector and you don’t allow the solder to wick too much up the wire they can be reliable, I have stuff I did 40 years ago on bikes and speaker systems that’s still working fine. Some grease to keep the moisture out is always good.
Has to be said, some of the snap connectors you can buy really don’t work very well, don’t grip the bullets securely. Some don’t actually “snap”. Squeezing to tighten them doesn’t always work either.
Some very good advice there so thanks for all that it is very helpful , from the engine i have 3 wires , 2 go to the rectifier marked AC where does the other one go to, the colour is a bit faded but i think its green/yellow , also can i put a 12 volt reg/rec on a 6 volt bike as hard to find a 6 volt one that is not expensive. regards
Hi,
Hth?
Regards,
I've already posted - You Cannot Continue To Use The Old Rectifier - the alternator output requires rectification and regulation, the rectifier on its own cannot do regulation, I've posted links to a cheap and reliable combined regulator/rectifier in post #7. If you use that reg./rec., each wire from the alternator stator connects to a different Yellow wire plugged into the reg./rec.
It's not "a 6 volt bike", DC Volts are whatever regulation you select; if you use the reg./rec. I've suggested, DC will be regulated to 12V. However, in addition to the reg./rec., you'll need to change battery, ignition coil and lamp bulbs to 12V components. Now is a good time to replace incandescent bulbs with LED (Light Emitting Diodes).
Hth?
Regards,
Hi Stuart could you please explain why i cannot just use the old system as that is what it had ,all i have changed is put a different headlight with 6v bulb & same with the rear , and put a different ign switch , i am not understanding why it would not work now , , this would be helpful if i knew why
Regards
Regards
Hi,
I'll attempt to fill in the gaps.
The existing alternator, all alternators that'll fit these old heaps easily, most motorcycle alternators are "permanent magnet" - the rotor is permanently magnetised; this is for simplicity, controlling alternator output by using the rotor as an electro-magnet (as on most other vehicles) is more complicated.
All motorcycle alternator stators consist of a number of coils of wire. The magnetised rotor passing these static coils induces electron movement in the coils, the electron movement is the basis of any alternator's output.
The only regulation a permanent-magnet alternator has itself is its rotor speed - the faster the rotor spins, the greater the stator output, although it isn't linear. Because this is isn't useful at high rotor rpm when little of the alternator output is being used - e.g. a run in the countryside on a sunny day, no lighting in use, battery fully-charged - the alternator stator must be connected to something that "uses" the output not being used by anything else electrical; this "something" turns otherwise-unused output into heat.
Your bike's "old system":-
. Like all Lucas motorcycle alternator stators before summer 1978, your bike's existing stator has six coils - illustrated on TIM4 page 136 - as TIM4 page 135 refers, the six coils are connected together internally in three series pairs - one end of one coil in a pair is connected to one end of the other coil in a pair.
. Externally:-
.. the Light Green wire is connected to one end of all three pairs;
.. the Green/Yellow wire wire is connected to the other end of two of the three pairs;
.. the Dark Green wire is connected to the other end of the third pair.
. Light Green and Dark Green wires connected to different rectifier AC terminals mean the stator coils pair between those wires provide the small amount of power necessary to run just the ignition and keep the battery charged for "occasional-use consumers" such as the brake lamp and horn.
. Engine running, ignition switch part of the PRS8 not in its "Emergency position", the output of the other two stator coils pairs was (sort-of) "regulated" by the setting of the lighting switch part of the PRS8. Significant here is TIM4 page 137 wiring diagram shows:-
.. stator Dark Green is also connected to PRS8 terminal 7 (a lighting switch terminal);
.. stator Green/Yellow is connected to PRS8 terminal 16 (an ignition switch terminal);
.. but misprinted is the diagram doesn't show stator Light Green (the wire common to one end of all three stator coils pairs) connected to PRS8 terminal 4 (another lighting switch terminal).
PRS8 Ignition switch On and Lighting switch Off, stator Green/Yellow (one end of the two stator coils pairs) and Light Green (other end of the two stator coils pairs) were connected together through the PRS8:-
. Green/Yellow terminal 16 was connected within the switch to terminal 17;
. Ignition switch On connected terminal 17 internally to terminal 18;
. terminal 18 was connected within the switch to terminal 5;
. Lighting switch Off connected terminal 5 within the switch to terminal 4.
This means the the power generated by these two stator coil pairs doesn't reach the bike's DC, the short-circuit generates a small amount of heat, that's radiated from the stator coils, the wires connecting them to the PRS8 and the PRS8 itself. Note also on TIM4 page 135:-
TIM4 page 135 continues:-
. Green/Yellow terminal 16 was connected within the switch to terminal 17;
. Ignition switch On connected terminal 17 internally to terminal 18;
. terminal 18 was connected within the switch to terminal 5;
. terminal 5 was connected within the switch to terminal 6 ...
... however, Lighting switch On connects terminal 6 to terminal 7, terminal 7 had the Dark Green wire connected, to the same rectifier terminal as the Dark Green wire from the stator, the rectifier was rectifying the output of all six stator coils, but only when the Lighting switch was in the "HEAD" position.
The significant failure of this type of alternator output regulation is it wasn't automatic; if something as simple as the headlamp bulb failed, because the Lighting switch was in the "HEAD" position, the full alternator output was still entering the bike's DC electrics ... usually the battery boiled, dripping and spraying its sulphuric acid on the bike; today, AGM or gel battery in use'll be 'blown'.
This is exactly why Triumph ditched this type of "regulation" - for automatic regulation - sixty years ago.
Hth.
Regards,
Are you sitting comfortably?
The PRS8 switch was central to what passed for alternator output regulation. Triumph Instruction Manual No.4 page 135 describes how the regulation is supposed to work, although it's a bit hard to relate to the wiring diagram on page 137 as that's incomplete and has at least one misprint.
I'll attempt to fill in the gaps.The existing alternator, all alternators that'll fit these old heaps easily, most motorcycle alternators are "permanent magnet" - the rotor is permanently magnetised; this is for simplicity, controlling alternator output by using the rotor as an electro-magnet (as on most other vehicles) is more complicated.
All motorcycle alternator stators consist of a number of coils of wire. The magnetised rotor passing these static coils induces electron movement in the coils, the electron movement is the basis of any alternator's output.
The only regulation a permanent-magnet alternator has itself is its rotor speed - the faster the rotor spins, the greater the stator output, although it isn't linear. Because this is isn't useful at high rotor rpm when little of the alternator output is being used - e.g. a run in the countryside on a sunny day, no lighting in use, battery fully-charged - the alternator stator must be connected to something that "uses" the output not being used by anything else electrical; this "something" turns otherwise-unused output into heat.
Your bike's "old system":-
. Like all Lucas motorcycle alternator stators before summer 1978, your bike's existing stator has six coils - illustrated on TIM4 page 136 - as TIM4 page 135 refers, the six coils are connected together internally in three series pairs - one end of one coil in a pair is connected to one end of the other coil in a pair.
. Externally:-
.. the Light Green wire is connected to one end of all three pairs;
.. the Green/Yellow wire wire is connected to the other end of two of the three pairs;
.. the Dark Green wire is connected to the other end of the third pair.
. Light Green and Dark Green wires connected to different rectifier AC terminals mean the stator coils pair between those wires provide the small amount of power necessary to run just the ignition and keep the battery charged for "occasional-use consumers" such as the brake lamp and horn.
. Engine running, ignition switch part of the PRS8 not in its "Emergency position", the output of the other two stator coils pairs was (sort-of) "regulated" by the setting of the lighting switch part of the PRS8. Significant here is TIM4 page 137 wiring diagram shows:-
.. stator Dark Green is also connected to PRS8 terminal 7 (a lighting switch terminal);
.. stator Green/Yellow is connected to PRS8 terminal 16 (an ignition switch terminal);
.. but misprinted is the diagram doesn't show stator Light Green (the wire common to one end of all three stator coils pairs) connected to PRS8 terminal 4 (another lighting switch terminal).
PRS8 Ignition switch On and Lighting switch Off, stator Green/Yellow (one end of the two stator coils pairs) and Light Green (other end of the two stator coils pairs) were connected together through the PRS8:-
. Green/Yellow terminal 16 was connected within the switch to terminal 17;
. Ignition switch On connected terminal 17 internally to terminal 18;
. terminal 18 was connected within the switch to terminal 5;
. Lighting switch Off connected terminal 5 within the switch to terminal 4.
This means the the power generated by these two stator coil pairs doesn't reach the bike's DC, the short-circuit generates a small amount of heat, that's radiated from the stator coils, the wires connecting them to the PRS8 and the PRS8 itself. Note also on TIM4 page 135:-
Simply, Lighting switch "In the "PILOT" position" no longer connects terminal 5 to terminal 4.
TIM4 page 135 continues:-
As above:-
. Green/Yellow terminal 16 was connected within the switch to terminal 17;
. Ignition switch On connected terminal 17 internally to terminal 18;
. terminal 18 was connected within the switch to terminal 5;
. terminal 5 was connected within the switch to terminal 6 ...
... however, Lighting switch On connects terminal 6 to terminal 7, terminal 7 had the Dark Green wire connected, to the same rectifier terminal as the Dark Green wire from the stator, the rectifier was rectifying the output of all six stator coils, but only when the Lighting switch was in the "HEAD" position.
The significant failure of this type of alternator output regulation is it wasn't automatic; if something as simple as the headlamp bulb failed, because the Lighting switch was in the "HEAD" position, the full alternator output was still entering the bike's DC electrics ... usually the battery boiled, dripping and spraying its sulphuric acid on the bike; today, AGM or gel battery in use'll be 'blown'.
This is exactly why Triumph ditched this type of "regulation" - for automatic regulation - sixty years ago.
Hopefully now clear?
Be sure, if the bike 'worked' without the regulation done by the PRS8 says the alternator probably isn't working fully; frankly not surprising for a 66-year-old alternator that wasn't very powerful even when it was brand-new.
Even if you only ride the bike in daylight, unless you live on a remote island off the Scottish coast, you'll be riding with 21st century vehicles with bright LED lighting; you and your bike'll be invisible to other road users.
Hth.
Regards,
New reg/rec wire colours are 2 yellows a black & a red , instructions state if you have a 3 wire stator it can be converted to 12 volt by
connect stators green /black & green/ yellow together & then connect to yellow on the reg/rec
connect the stators green white to the other yellow , my stator colours are dark green , light green , green/yellow , any suggestions ? thanks
connect stators green /black & green/ yellow together & then connect to yellow on the reg/rec
connect the stators green white to the other yellow , my stator colours are dark green , light green , green/yellow , any suggestions ? thanks
The coil has nothing to do with the charging circuit, though if you're using a 6 volt coil with a 12 volt battery, it will get VERY hot!
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