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Gremlins in the electrics...

Posted: Thu Feb 15, 2024 10:28 am
by Jairhead
Hi all , and thanks for adding me to your group. I recently bought a 1983 R100RT, without the fairing. I managed to find one and have since fitted it. The only thing electrical was moving the ignition switch from the side of headlight to its proper position in the fairing. Now , when I turn on the full ignition, I get constant headlight. I've replaced the headlight relay , but same result. I've also tested ignition switch and it seems to be ok. What am I missing here. I'm desperate 👍😃
P.S. I omitted to say that it's a UK model , as I live in Ireland.

Re: Gremlins in the electrics...

Posted: Thu Feb 15, 2024 2:50 pm
by srankin
Two things come to mind, first is recheck the wire connector position on the back of the ignition switch. I found one time after an overhaul on my RT that it can be connected wrong and the bike will start and run with the headlight relay bypassed. This means the headlight is always on even when cranking the starter.

LOL, I don't have the exact wiring on hand, maybe tomorrow when I am in my shop I will try to see what wire goes where on the switch.

The other thing would be to check were things are plugged in on the main circuit board. Working in there is a tight space and if your headlight wiring looks like a bundle of jumping snakes, (not saying it does LOL) you could have a connection out of place. St.

Re: Gremlins in the electrics...

Posted: Sat Feb 17, 2024 12:04 pm
by srankin
20240217_121049.jpg
Not quite sure if this will help, it is a quick diagram of the wires on the back of the ignition switch I made. St,

Re: Gremlins in the electrics...

Posted: Sun Feb 18, 2024 11:09 am
by Jairhead
Hi St.
Many thanks for taking the time to reply to my post. I haven't gone near the bike since Thursday. I've been away visiting family. I'm going to get stuck into again this week.
My plan is to start again, testing the ignition switch with multimeter. Then I'm going to try find whatever fault may be there inside the headlight. Failing all that , I'm going to sign myself in to a home for the bewildered......
Thanks for diagram. It looks similar ,although mine has 5 spades , one of which is an extra unused connection.
Again , thank you.👍☘️

Re: Gremlins in the electrics...

Posted: Sun Feb 18, 2024 11:21 am
by srankin
I didn't draw the unused connector, my switch also has five connections. St.

Re: Gremlins in the electrics...

Posted: Sun Mar 10, 2024 7:48 am
by Jairhead
EUREKA.....
I've managed to solve my "gremlins in the electrics". After replacing both headlight and starter relays without any success, I went through the whole bike . I found other issues , bad earths , bad connections and the usual wear and tear with old wiring. I fixed all these problems but still had the headlights coming on with the ignition switch. As a last resort, I removed the clocks assembly, and low and behold, the system worked as it should. I simply cleaned the electrical contact plug and reconnected the clocks assembly. I'm ecstatic.... something as simple as that. All works perfectly now and I don't feel that I wasted all that time. After all , I now feel that I've managed to refurbish quite a bit of my electrical system. I live in hope. Many thanks for the advice. Cheers from Ireland ☘️🇮🇪