Wiring faults on the G5

[ditchweed]

Hey Guys
Back working on the bike after not having anytime because of work for several months, got the engine and gearbox back together today it turns over and has compression so thats one thing, but charged and attached the battery, (+ to the frame) and was hoping for a light or some sort of activity when i switched to I but got nothing, and definitely no spark, has anyone got any tips for troubleshooting, or is it a matter of just checking each wire is correctly fitted and working with an avo meter, also still got the old rectifier does anyone have a way to test it, or is it worth just switching to solid state. and if i do that does it mean i then have to switch the battery terminals so - goes to the frame?
Thanks

[Stuoyb]

The solid state rectifiers can be wired +/- earth.

[Ozmadman]

Hey Guys
hoping for a light or some sort of activity when i switched to I but got nothing, and definitely no spark, has anyone got any tips for troubleshooting, or is it a matter of just checking each wire is correctly fitted and working with an avo meter
Thanks

Is the ignition switch working? you could always swap it for the light switch, as they are the same switch, and try that first, then it's a case of trial and error after that

[Rangy65]

As Paul suggests try swapping switches. Mine were the originals and looked ok, i rebuilt using a new wiring harness Swapped to 12v and negative earth and guess what no spark.

It was the original switch - replaced with new replica one and the bike started first kick.

Good thing to check is connection from battery to frame.

Are you getting power to the lights, horn, points etc?

Cheers
Steve

[ditchweed]

No power anywhere as far as i can tell, will go at it with a meter later and try and figure out where the power isn't getting to, good point about the frame will check under the connection that it is actually touching the metal not just paint. so is it possible to just swap the polarity or the circuit so - to frame, feels very unnatural having the + on the frame.

[ditchweed]

also does anyone know a place where there is a higher res scan of the G5 wiring diagram, seems most of them are pretty pixelly and hard to read.

[Colin F]

so is it possible to just swap the polarity or the circuit so - to frame, feels very unnatural having the + on the frame.

No you have to sort out the polarity of the rectification and if you have an original rectifier the mounting bolt is the +ve terminal.

No it is natural to have +ve earth, it's all to do with electroylis and anodes and cathodes and stopping metal being eaten away.

[Rangy65]

For my restoration i did not have much in the way of electrical stuff in the boxes of bits, so i did convert to Negative earth as i decided to upgrade to modern components and 12V.

I used a new harness, An AREG1 regulator/rectifier, all new switches, 12V battery, simple reconnection of the alternator wires to give 12V ( there is an article on how to do this in the lightweight technical section), upgraded 12V headlight bulb and LED rear and finally an in-line main fuse.

All my previuos bikes have been japanese or modern triumph so i find it easier to fault find on negative earth. ( its just what i have got used to).

The electrics work a treat no issues with charging and are very reliable.

There is no on/off key with these bikes so the horn and lights are always live... something to consider when you are fault finding.

cheers
Steve

[red_dog49]

hi, just rewired my LW with a new loom and all ok, I added a couple more earth wires around the bike engine and frame
as the earth post (rectifier fixing) on the rear mudguard didn't look very efficient to me.
remove the wires from the rectifier if you want it does nothing until the engine is running.
use a voltmeter, do the volts drop off when you connect negative to battery
use an ammeter, is there any current when you connect the negative
has someone fitted a fuse anywhere and hidden it.
check the earth circuit with a voltmeter.
try and be logical, start at battery and work away.
regards
Rob.

[Ozmadman]

also does anyone know a place where there is a higher res scan of the G5 wiring diagram, seems most of them are pretty pixelly and hard to read.

Don't know if this is of any use to you but this is the wiring diagram made by the guy who rewired my bike for the P.O just before I bought it