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Just finished restoring a 67 Bonney, installed boyer elec. Ignition and podtronics. I have power to the coils and plugs until i install the ground wire from coil to frame. All is dead if i install the ground wire. Why. I have no spark at the plugs when i kick over engine . Can anyone help. I have done all the tests, but get no spark at the plugs.
 

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Hi,

Firstly, welcome to the Forum. :)

67 Bonney,
have power to the coils and plugs until i install the ground wire from coil to frame. All is dead if i install the ground wire.
Standard 'positive ground' or converted to 'negative ground'?

Nevertheless, 'fraid you're confused and you've wired something else wrong:-

. You cannot "have power to the coils and plugs" without that connection between one of the coil LT terminals and the battery "ground" terminal ('positive' or 'negative'); if you do, the electrics are making a connection to the battery 'ground' terminal somewhere else.

. The Boyer-Bransden fitting instructions are crap at explaining this:-

.. the frame is not "ground", it's just a piss-poor electrical connection to one of battery terminals (battery +ve as standard);

.. if your bike has standard 'positive ground' electrics, the wiring harness has Red wires from most of the electrical components to the battery +ve terminal; the wire from the second coil "+" terminal is better connected to these Red wires at one of the existing snap connectors.

Hth.

Regards,
 

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Discussion Starter #3
Hi,

Firstly, welcome to the Forum. :)


Standard 'positive ground' or converted to 'negative ground'?

Nevertheless, 'fraid you're confused and you've wired something else wrong:-

. You cannot "have power to the coils and plugs" without that connection between one of the coil LT terminals and the battery "ground" terminal ('positive' or 'negative'); if you do, the electrics are making a connection to the battery 'ground' terminal somewhere else.

. The Boyer-Bransden fitting instructions are crap at explaining this:-

.. the frame is not "ground", it's just a piss-poor electrical connection to one of battery terminals (battery +ve as standard);

.. if your bike has standard 'positive ground' electrics, the wiring harness has Red wires from most of the electrical components to the battery +ve terminal; the wire from the second coil "+" terminal is better connected to these Red wires at one of the existing snap connectors.

Hth.

Regards,
Thanks for the welcome and your reply. I'm quite certain my problem lies with a grounding issue as 9 out 10 electrical issues are. I have a single point ground terminal mounted to the side of the L shaped aluminum heat sink that the original Zener was mounted to, I have a dedicated wire from the headlight, taillight ,battery and podtronics unit going to this point. I have my boyer box mounted with two sided foam tape to the outside of the battery box. I just tried switching all over to negative ground to see if it made any difference and same result- power everywhere until I ground it, then all dead. No spark at the plugs .
 

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Hi,

single point ground terminal
I have a dedicated wire from the headlight, taillight ,battery and podtronics unit going to this point.
To be clear, a Direct Current electrical circuit on the bike is only from battery negative to battery positive.

Risking telling you things you know already "battery negative to battery positive" is significant; "ground" does not exist in DC electrics, therefore "positive ground" and "negative ground" are merely concepts, irrelevant to the actual electrics. Standard '67 British bike electrics, the "single point ground terminal" as you have it is just an extra connection between any electrical component and battery +ve.

Aside, the Podtronics (any combined regulator rectifier) should have its Red wire connected directly to the battery +ve terminal and its Black wire connected directly to the bike's original rectifier Brown/White wire - the latter connection ensures the Ammeter continues to show both charge into and discharge from the battery. Connecting the Pod Red wire to anything else is simply an extra - usually exposed - connection between the Pod and battery +ve, that doesn't achieve anything except reduced long-term reliability.

tried switching all over to negative ground to see if it made any difference and same result- power everywhere until I ground it, then all dead. No spark at the plugs
Because "ground" does not actually exist on your bike, if it has "power everywhere" and "spark at the plugs", there must be one or more complete circuits from battery -ve to battery +ve.

As a start to trouble-shooting, I suggest following the complete ignition circuits (plural) wiring from battery -ve through the B-B Transistor Box and back to battery +ve. For standard ("positive ground" :sick:) '67 Britbike DC electrics, the circuits are:-

. Brown/Blue wire -> Ammeter -> Brown/White wire -> Ignition switch -> White wire -> Boyer-Bransden Transistor Box ->:-

.. First circuit continues -> Transistor Box Red wire -> battery +ve. To be clear, this wire is the battery +ve connection for the Transistor Box electronics only, it does not have to be connected to the "+" terminal on the coil labelled "HT2" in "FIG.3." of Boyer-Bransden fitting instructions (fwiw, "positive ground" electrics, connecting this Red wire direct to the battery +ve terminal is something I've always done).

.. Second circuit continues -> Transistor Box Black wire -> one coil "-" terminal -> that coil "+" terminal -> second coil "-" terminal -> second coil "+" terminal -> battery +ve; that said, this last could be connected to your "single point ground terminal".

.. I notice "dedicated wire from" the engine to your single point ground is missing from your posted list; if it's missing in reality on your bike, be aware - with single HT-terminal coils - the "dedicated wire" is much better for long-term HT reliability than completing the circuit through random connections between bits of bike and other wires.

Hth.

Regards,
 

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Thanks Stuart, I have wired according to Boyer/Podtronics instructions and all things point to a faulty Boyer box. I have another Boyer set enroute for another project and will try using that boyer box temporarily to see if then works. I installed a new wiring harness and all things work as they should( other than horn is always live ??) and the boyer and podtronics are pretty simple to install(according to their instructions). I will go to your instruction and hope it helps. I did try adding a dedicated wire from engine to my single point ground via a jumper wire, but it didn't make any difference but will install one regardless. Thanks for your help. I attached a diagram of how I wired the boyer/Pod units.
Regards
 

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Hi,

installed a new wiring harness and all things work as they should( other than horn is always live ??)
The pre-'71 principle was the horn could be sounded even if the ignition switch was off. So one horn terminal is connected directly to battery -ve with a Brown/Blue wire, the wire from the horn to the handlebar button is Brown/Black. Pressing the button connects it to the handlebar, then the Lucas 'magic ground' connects the handlebar to battery +ve through random connections between bits of bike ... :rolleyes:

Reading between the lines of your last post, I'm suspecting you have an aftermarket or pattern horn that isn't isolated from its mounting - every time you connect the Brown/Blue wire, it sounds? If so, the horn's making an electrical connection through it's mounting and back to battery +ve through bits of bike to your single point ground. If so, you need a horn isolated from its mounting ... :)

When you have the correct horn, maybe also consider bypassing the 'magic ground' with proper electrical wire and terminals to battery +ve:-

. Most ideal but hardest in practice is a new fifth (Red?) wire alongside the standard four to the combined horn/dipswitch; you have to work out where the horn button touches the switch body to close the horn circuit and solder the fifth wire to the switch body, but without causing a short from the headlamp hi/lo switch ...

. Easier alternative is allow the horn button to connect through the switch body and handlebar mounting screws, then attach the new wire to the handlebar, say at one of the top yoke clamp bolts?

. Thread the wire into the headlamp shell and connect its end with a bullet terminal into an existing Red wires' snap connector.

Other electrical parts Lucas intended to operate with 'magic ground' are the speedo. and tacho. bulbs, but their mounting is connected to the top yoke through rubber bushes ... 😖 Wise is a wire from the "Mounting bracket" into an existing Red wires' snap connector in the headlamp shell.

I attached a diagram of how I wired the boyer/Pod units.
(y) Only change I'd advise ime: the wire from "6 VOLT COIL 1" to "GROUND ON FRAME PAINT REMOVED", move the latter end to your "SINGLE POINT GROUND".

Hth.

Regards,
 
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