I'm having a elec. prob with my 1975 R75/6. It fails on indicators (blinkers), brake light, and horn. I can't figure out the prob. I checked the indicator relay, no prob there. All fuses ok. I can't locate where an electrical prob would be that would effect these three features?? Any help from the collective consciousness welcome. Thanks...
Maith an fear ! My instinct is that you have a ground problem rather than a 12volt suppply problem. But then again i could be right out to lunch. Good luck with your problem.
I think you should recheck the fuse positioned in the "15" terminal in the headlight shell. It appears that all of these devices get power through that fuse. Fuses might look OK, but they really need to be checked with an ohmeter. Also, the contacts in the headlight shell could have corrosion on the ends. Be sure they're clean.
Grounds can be a problem in DC circuits, but because these three circuits share power, that seems to suggest that as the problem.