Wiring Schematic & Intermittent Fault

Information related to the Harris Matchless (also known as Devon Matchless)
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velocollins
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Joined: Thu Feb 16, 2023 4:50 pm
Location: Herts UK

Wiring Schematic & Intermittent Fault

Post by velocollins »

Purchased Harris Matchless G80 last year as non-runner. Making progress and it now runs but has some intermittent electrical problems and I could do with acquiring a full electrical schematic for the bike. Does anyone have access to the full wiring diagram as the original owners manual is not specific enough.

One key problem is that the Red Ignition charging light works intermittently when the ignition is first turned on. Neutral light and lights always work when ignition is turned on, but Red ignition light will not always come on and this then appears to affect the starting and spark to plug. Originally thought it was just bulb holder or bulb but this has now been eliminated.

I have reviewed the wiring and connectors and all of a sudden the light will come on and the bike starts but have not been able to isolate the actual root cause.

Thought appreciated. Richard
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clive
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Re: Wiring Schematic & Intermittent Fault

Post by clive »

Sounds like a dodgy connection in the ignition switch to me . Try connecting the ignition wires without the switch. If that consistently works then you have found te problem.
clive
if it ain't broke don't fix
velocollins
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Re: Wiring Schematic & Intermittent Fault

Post by velocollins »

clive wrote: Thu Feb 16, 2023 8:33 pm Sounds like a dodgy connection in the ignition switch to me . Try connecting the ignition wires without the switch. If that consistently works then you have found te problem.
Clive, thank you for your input. I suspect there may also be a bad earth, but life would be so much easier with a full wiring schematic. Regards. Richard
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clive
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Re: Wiring Schematic & Intermittent Fault

Post by clive »

One other thought in the 70s I had these symptoms on a mini, turned out to be corrosion on I think it was the negative terminal connection to the battery. A sort of white growth. Cleaned it off and spread some specially bought copper based grease and the problem went away. Never had it since on any other vehicle and 98% of the tube of special grease is still sitting in the garage!

Cannot help with the wiring diagram I am afraid.
clive
if it ain't broke don't fix
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Andy.S
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Re: Wiring Schematic & Intermittent Fault

Post by Andy.S »

FOUND THIS ON FACEBOOK.

velocollins
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Re: Wiring Schematic & Intermittent Fault

Post by velocollins »

Andy, Thank you for forwarding the Ignition drawing.
DaveTanner
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Re: Wiring Schematic & Intermittent Fault

Post by DaveTanner »

Did you get to the bottom of the fault as I had similar problems when I first had mine. Mine has electric start.
On these the ignition is by magneto, you don't need the battery at all for that. A common fault is the prop stand switch which works in conjunction with the kill switch. They both work by earthing one feed to the ignition amplifier box. you can disconnect it to prove the fault.
My fault with the ignition/charge light was down to a poor connection on the ignition switch, when the handle bars were moved the fault came on causing loss of inddicators and battery charging. I actually replaced the the wires to the headlamp and the fuse box as mine had been got at in that department. I do have the full wiring diagram if you need it
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