1979 GS750 - No electrical when wet/humid

[Farnworth]

Hello,

I have an intermittent issue that I can't pinpoint.

If I try to start my GS in the early morning when it's cold and there's dew everywhere, there's no electrical power at all (no headlight, turn signals, horn, starter, etc.) I cannot get it started with the kickstarter either.

I have to wait until the sun comes out and it dries up a bit, then everything works perfectly fine.

I've tried playing with the key switch, the engine on/off switch and pulling/tugging on some wires, but still no electrical.

Does anyone have a hint of what I should check?

Thanks.

 

[Grimly]

Duff connection somewhere that's marginal, at best.
Start from the battery - clean those terminals first.
Check the cleanliness and tightness of the heavy gauge wires on the starter solenoid.
Check your fuse holder(s) - I think there's only a main single fuse on yours, but you might have the 4/5-way fusebox.
Check the tightness of the main engine ground lead where it bolts onto the casing - runs from the battery negative to there.
Access as many of the connectors on the main harness as you can and clean and tighten them - there are no shortcuts in this.
Take off the headlamp and do the same in the shell.
Good luck!

 

[Farnworth]

For anyone searching this in the future, it ended up being the key switch. First thing I suspected and was lucky it was it (I redid all my wiring and grounds last year). The contacts inside just needed a little cleaning.

Cheers!