Britbike forum Forums Thread Like Summary - A10 wiring advice sought

It is a 1963 RGS, but has been rebuilt and rewired so much that its original configuration has all been changed over the years. I have had it over 50 years. It sat up for most of the summer, the floating charger got pulled off, and the battery had to be replaced. Ok, with the new battery it cranked first kick. Nice.

But the voltage across the battery does not increase when the engine is revved, and there is no power inside the headlight shell. I am trying to trace out the wiring without too much disassembly, and cannot remember what is the finned unit that looks like a heatsink behind the battery mounted on the rear fender. It has a Black, Red, and two White wires coming out. Black goes to Positive ground, and the other three disappear into the harness.

Installed are a Boyer 12V Micro-MKIV ignition (p/n BOX00023), a Wassell electronic ignition where the magneto used to be, and an Alton alternator inside the chaincase on the left. As I recall, the Boyer functions more as a regulator than a Boyer points replacement kit, but I really don't know.

What is the finned unit behind the battery with the four wires? And where should the wires go? Maybe if I knew that I could figure out the wiring and repair it.
Thanks in advance. You are all always so helpful.
Rick

There are Wassell housings which fit in place of the magneto and can hold a Lucas 4CA or 6CA points set, or a trigger rotor and stator for an electronic ignition, which can be Boyer or Wassell/Vape, or (probably) even Lucas Rita.

Is that what you’re trying to describe?

the finned unit sounds like a voltage regulator to me. maybe something like a Podtronics? except the alternator wires are yellow on the Pod. I would think Red & Black would be the DC plus/minus and the 2 whites would go to the alternator. did it ever work in the past? is so it sounds like the polarity was changed


and the ignition... Boyer and a Wassell??? how could that work?

Black on a regulator is unlikely to go to positive.

yeah, thats what I was implying... . hence the question in my post... did it ever run like that?

the ignition system is polarity sensitive too. anything that has seen reverse polarity is suspect

4 wire, black box rectifier/regulators ... mostly have a standard wire color convention .
... the 2 white wires are... probably 2 yellow wires ... and go to the alternator ( stator) (both of these are equal ac connections )
and the
black is DC negitive
red is DC positive
( these DC outputs can be wired as positive or negative ground )

what polarity has been chosen for the bikes ground ?
( what polarity runs through the ignition switch ) ... the earth-side will be the opposite of the switch-side

The sequence of wires is irrelevant , it may change brand to brand , or within a production run .
its the wire colors that have become standardized to purpose .


the black regulator wire should never go to battery positive terminal
( black is negative ... goes to battery negative terminal... irrespective of bikes ground )

... I don't know the bikes polarity ... but if you say ...the ignition works with the way the battery is currently wired
the battery is in the right position for the ignitions polarity ( the ignition would not work if the battery was backwards )

... what I think is wrong ... is the regulators connection to the battery ...

the Boyer 12V Micro-MKIV ignition (p/n BOX00023 ) is an ... ignition module ( double check what you think you have , or what the guy sold you against ..what you have )

boyer also ... makes some regulator/rectifier units ( power boxes ) , perhaps you have one of these ... but these dont have fins


a vape ignition has its own module ( seen below ) ( so it does not make sense that you would have two different ignition modules )
... incidentally , these are wired the same as most Boyers and Pazons

If the bike runs , the ignition is running off the battery , which is good , its halfway there .
( the charging system is a completely different circuit ... that can take over and run the ignition and lights
and Drive the battery back into a state of re-charging
... when-ever the charging circuit output voltage ... is slightly higher than battery voltage )

shown below is a podronics voltage regulator ( typically a small finned and potted black box )
. ( but the brand doesn't matter ... all 4 wire Regulators ... that I've seen ... have the same polarity colors )
black wire is negative ... goes to battery negative
red wire is positive ... goes to battery positive
( the ground side is whatever side of the battery you have chosen for ground ... )

not charging ? ( the charging circuit is broken at some point )
1. stator is bad ( spinning rotor magnets induce AC voltage in the stator coils) ( check for AC .. under load or open )
2. Wiring from stator to regulator is bad ( 2 yellow wires that terminate inside the black box)
3. Regulator is bad ( you can check AC input and DC output )

4. Regulator output is not hooked up ( or is not hooked up with the correct polarity ).
If it ran and charged before storage , my money is on number 4.
Rechecked to see that the black wire runs to battery negative
and the red wire runs to battery positive

5. For extra credit ... where are any fuses ?

Hi Rick,
There may be 2 separate issues going on?
What is the new battery voltage reading ? if it is above the regulator cut off point then the bike will not charge
A separate issue is the headlight lack of power?
If the bike has just been rebuilt it could be a lot of different things
Have you tried to measure the voltage at the ammeter?
Does the bike still have the QD plug at the headlamp? these can cause problems with loose pin/ socket fitting
If the frame has been re painted or powder coated then lack of a good earth return path from the headlamp could be an issue??

John

Hi Rick,
Reading back to your first post I saw that an Alton alternator is fitted, I'm presuming that it is fitted to the dynamo location?
Usually the Alton is supplied with their own rectifier regulator/ rectifier, this may account for the odd coloured wires and wiring ???
Do you have any information or paperwork that came with the Alton?
Disconnect the two white/yellow wires, connect a 65watt 12v headlamp bulb across the two wires coming from the alternator
start the bike and the bulb should light brightly, (probably flickering) do not rev the engine high as this will pop the bulb
This should test the alternator output

Set a multi meter to continuity (or circuit tester) connect one lead to wires that connect to the live side of the battery (battery disconnected)
use the other lead to look for continuity at the ammeter?
You did not answer my question on the QD headlamp plug? If no continuity at the ammeter, unplug the QD connector and probe the pin that has the same colour wire as the battery connection, this should be a solid wire, You will probably find that the other 2 wires at the battery go to the horn and brake light switch?
Are there any fuses fitted ?
If the rectifier / reg battery connections were reversed then it will more than likely have died :-(

John