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Discussion Starter #1
Sure could use some help. Bike is a stock 67 Bonneville w/ a Boyer, Tympanium regulator and new, made in England, cloth covered wiring harness.
I’ve installed the harness using the diagram in the Triumph manual but have problems with the lights at both ends.

1. High beam only, no main beam. (bulb is good)
2. Brake light is working but when lights are on and brake applied the brake light does not become brighter.

The diagram indicates a blue/red wire for main beam. This harness has solid blue and blue/white but no blue/red.
There is a solid brown wire in the headlight bucket coming from the handlebar dip switch/horn button.
Thanks for any help, I’m stumped!
 

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The blue wire from the harness should connect the light switch to the headlamp dipswitch on the handlebar (ie it provides the power to the dipswitch when the lightswitch is set to Main lights). The bluewhite and blue red then flow from the dipswitch, to main and dip filaments respectively.
If the blue/red doesn't exist, I'd suggest testing that brown wire to see if it gives 12V when dip is selected. If so, it's just the harness maker has been a bit cheeky with wire colours.
Note the blue/red doesn't exist in the main harness, it is one of the wires from the dipswitch.
It isn't clear what your #2 issue means, but it is most likely a stuck on brake switch and/or the wires to the brakelight and tail filaments being exchanged. Assuming there is a good and correct ground for the bulb.
 

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Hi,

stock 67 Bonneville
I'm assuming 2-position (on/off) key ignition switch in the sidepanel and rotary lighting switch in the headlamp bucket.

High beam only, no main beam.
For clarity, "High beam" and "main beam" are the same - the one that dazzles oncoming drivers; :whistle the other one is 'low beam' or 'dip (beam)'.

new, made in England, cloth covered wiring harness.
harness has solid blue and blue/white but no blue/red.
So I'm guessing this is really a Wassell "Genuine Lucas" :rofl Indian-made harness that they then shipped to GB and had someone crimp on one bullet so they (Wassell) can take the piss out of "Made In England" ... :bluduh

"solid brown wire in the headlight bucket coming from the handlebar dip switch/horn button" says the switch is pattern; it should have four wires:-

. one'll be from the horn to the horn button (originally Brown/Black);

. one'll be from Lighting switch to dip switch (originally Blue);

. one'll be from dip switch to headlamp 'low beam' or 'dip beam' (originally Blue/Red);

. one'll be from dip switch to headlamp 'high beam' or 'main beam' (originally Blue/White).

As the headlamp, the Lighting switch and the wires from the handlebar dip switch/horn button are all in the headlamp bucket, nothing is served by Blue or Blue/White wires in the main harness. :cool: When you've worked out which handlebar dip switch/horn button wire is which function, just connect:-

. what should be the dip switch solid Blue wire directly to Lighting switch terminal #3;

. what should be the dip switch Blue/Red wire directly to the Blue/Red(?) into the headlamp bulb;

. what should be the dip switch Blue/White wire directly to the Blue/White(?) into the headlamp bulb;

. if your bike's headlamp bucket has the high beam/main beam warning idiot lamp, connect its Blue/White(?) wire at the same place as the dip switch and headlamp wires connect.

Brake light is working but when lights are on and brake applied the brake light does not become brighter.
If Chris's advice to check for "a stuck on brake switch and ... wires to the brakelight and tail filaments ... exchanged" doesn't find the problem, there is another well-known possibility.

Remove the rear lamp lens and ascertain, when you pull or press a brake lever to actuate the brake light, only the brighter of the two bulb filaments illuminates.

If it does, turn on lights and ascertain only the dimmer of the two bulb filaments illuminates.

If it does, with the lights still on, again pull or press a brake lever to actuate the brake light; if the brighter of the two bulb filaments now doesn't illuminate, the problem is the return path from the bulb to battery +ve (aka "ground") isn't working. This is a possibility if you installed the new harness as part of a restoration that included new frame and/or fender paint, :) or the bike has sat around unused for many years? :(

If new paint, I recommend against scraping any off to expose bare metal ... that'll rust and rust conducts electricity as well as good paint ...

Ideally, run a new (Red) wire from an existing Red wires bullet snap connector under the seat, beside the rear lamp Brown and Brown/Green wires into the lamp and solder the end to the outside of the bulb holder.

However, if it's difficult to run the new wire into the lamp itself beside the two existing wires, I terminate the new Red wire with a 3/16" ID ring terminal and attach it under the nut on one of the rear lamp mounting studs. If you do that, (use your meter to) check there is a return path from the bulb holder to the stud - original Lucas lamp holders are in two parts, they were originally joined electrically by a truly minute piece of braid but, more that half-a-century later, who'd be surprised if the braid had been lost or rusted away? :Darn

Hth.

Regards,
 

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Discussion Starter #4
Thanks Chris and Stuart.

Yes, 2 position key in the side cover and a rotary light switch on top if the headlight.

Headlight
There are 4 wires from the dip switch:
Red/black, the horn, is working.
Blue, connected to blue from light switch
Blue/white, high beam working
Brown, no power when dip beam is turned on.

Tailight
Brake light switch is free and not stuck.
Lamp unit has two wires, black and red. (red is grounded to the single point ground then directly to battery positive).
Currently, both brown and brown/green wires from the harness are connected via double snap connector to the black wire of the lamp unit.
Only the lower filament illuminates for BOTH brake light and running light but does not brighten if running light is on and brake is applied.
Top filament not lighting at any time.

The bike is a resto, the original harness went up in smoke last summer. The bike frame parts are powder coated.

Appreciate your time and input, would like to get this bike running,
 

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I'd suggest taking the dipswitch cover off. Ii's function is then plain to see.
The supply from the light switch must go to the centre pole of the dipswitch (the one in the lever). The high and low beam wires come from the poles to either side.
I suspect that the switch has been wired by a PO in a confused manner, with the blue/white going to the centre pole, rather than the blue as it should be. The power from the light switch will then be going to one of the side poles, which will allow the bulb filament connected to the blue/white wire to work but not the other filament. This is what you are reporting.
The only other possible alternatives are that the brown wire isn't installed in the switch properly, that side of the switch is faulty, the connection in the bulb holder isn't being made for the other filament, or the other bulb filament is blown.

With the tail lamp, I don't think that the red wire is meant to be a ground at all.
It is easy to check that both wires go to the pins that contact the bulb terminals just by pushing the wires through the housing to reveal where they go. If both wires go to the bulb pins, this is proof. The use of a multimeter would make this even simpler, this would also be the case with the headlamp issue.
If this is the case, completely remove the red wire from the ground network, separate the brown and brown/green wires from their shared snap connector, and feed each one separately to the 2 light unit wires. My guess is that the brown wire should connect to the red (just swap them if that guess turns out incorrect).
Highly recommended would then be to supply a proper ground as Stuart advised.
 

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As has been surmised. The two wires from the tail lamp are power to the filaments. The lamp is designed to complete it's circuit through the components of the bike, not very reliable unfortunately. Run a seperate cable as Stuart has suggested and then connect the black and red to the power feeds for stop and tail lamps, you have a 50% chance of getting it right first time!

On a seperate note, those cheap Mickey Mouse reproduction tail lamps are horrible. I went through 3 or 4 before spending the extra money on a proper NOS Lucas unit.

Rod
 

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Discussion Starter #7
Tail lamp connected as suggested, still only one filament is working.
Dip switch not operable. I’ll be ordering Lucas parts this week.
Thank you again all who contributed.
 

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Hi,

Tail lamp connected as suggested, still only one filament is working.
Which suggestion though? If you have only connected the main harness Brown/Green wire to one rear lamp wire and the main harness Brown wire to the other rear lamp wire, you still likely need a new third wire from the bulb-holder or mounting stud to the main harness Red wires under the seat.

Otoh, if you've installed the third wire as I advised, you need to get out your multi-meter (you do have one?) and check for continuity at various places. Be a bit more specific about what you've done already and we can try to suggest further progress.

Regards,
 

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If you're not using a multimeter, at least make certain that both filaments of your headlamp and tail bulbs work. Otherwise you'll be chasing a ghost.
 

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Discussion Starter #10
Both tailight/brakelight are now fully functioning. The contact points within the lamp socket were askew, not positioned to fully meet/seat the bulb! I have added a dedicated ground from the lamp socket to battery positive via the SPG. Very bright lights now.

RE the dip beam, I ran out of time this day to look into the contacts within the dip switch. Hope to get to that tomorrow and will report back.
Thanks fellas, this bike’s gonna run soon.
 

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Discussion Starter #11 (Edited)
Dip beam, and high beam now working, tail running lights also. As Chris suggested, the blue/white wire was/is connected to the side pole within the handlebar switch! Brown does supply power from switch.
A switch designed to baffle, it would seem.

All lights now very bright, working great.

Please, what is the correct color lens indicating the high beam is on, red or green? That too is working.

Thanks Chris, Stuart and Red for your time and patience.
 

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Hi,

Dip beam, and high beam now working, tail running lights also.
Excellent. :thumb The Forum does like a happy ending. :D

A switch designed to baffle,
Not originally; although cheaply-made, originals did at least have the correct wire colours. Unfortunately, your bike's original likely fell to bits at some time and was replaced by a pattern one, that was even-more cheaply-made, to the extent that the maker couldn't even be bothered to get the correct wire colours. :bluduh Some I've seen new with different wire colours do come with a bit of paper detailing the new connections but, if your bike's ever had one, whoever fitted the switch didn't bother to retain it? You can buy the correct wire colours for the switch wrapped up in a piece of black sleeving; all you have to do is unsolder the existing ones from the switch and solder on the new ones. :thumb

Finally here, be aware the 'ground path' from the horn button back to battery +ve is pretty crap - it's through the switch screws into the handlebar, then through some convoluted path through bits of bike :ThrowUp so there's a real risk the horn circuit can stop working at any time, perhaps unnoticed for a while if you don't use the horn very often; :( not something you want to discover when you really need the horn ... I include a fifth - Red - wire, soldered to a convenient point on the switch body at one end and connected into an existing Red wires' snap connector inside the headlamp shell at the other end.

correct color lens indicating the high beam is on, red or green?
Green. For some bizarre reason, it was decided during 1967 that Lucas would supply complete headlamps fitted with first one idiot lamp and then two - Red and Green. Different bike makers used the lamps for different things, Triumph (and BSA) used Red to indicate the ignition was switched on and Green for headlamp high beam.

'69-on, Triumph (and BSA) connected the new oil pressure switch to the Red idiot lamp. Green remained high-beam on the triples 'til it was replaced by Blue on the T160 for '75; on the twins, Green remained high-beam 'til it was replaced by Blue for '79 (when the twins got the same top yoke, speedo. 'n' tacho. mounting and idiot lamps as the T160).

Hth.

Regards,
 

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Just to be pedantic, 67 650's all had two idiot lights. It was early in the 66 season that one idiot lamp was introduced, red to indicate ignition on. It was fitted centrally just below the ammeter in a position that was obscured by the speedo/tacho bracket. Soon after a green lamp was added again below the ammeter with the lamps now either side of centre. Once again they were obscured by the speedo/tacho bracket so the bracket was modified to include a relief between the two clocks.

I'll go hang my anorak up now,
Rod
 

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I have just changed the colours on my 68 Trophy blue for high beam and green for ignition, I did this as most vehicles I’ve owned use blue for high beam and red is usually an oil warning , so decided on green for ignition for go I also purchased an aftermarket switch/horn and wires were the same colours as original but switch was wired differently, took switch apart to see what went where and it all works fine now.


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