I have a 85 FXR evo, last ride when i would break my headlight would dim very bad, then after a few times breaking would kill headlight. Tested it in the garage not running just with key on, and stepping on break pedal a few times would hear one of the relays click the just headlight turns off, then turn key on and off a few times the relay clicks again when key off and headlight works again till the relay clicks again and all happens again. Does this mean that the relay is just bad??? not sure how to test it, I am a little electrical savvy but no expert by any means. Battery is fairly new, and haven't had any problems. Any help will be much appreciated thanks!!

 

Maybe this will help if you don't have one already.

 

This is one of those needles in a haystack! It could be as simple as a bad ground, or a chafed wire, somewhere. Not easy to diagnose, just needs some dogged determination to seek the darned thing out.

Bear in mind that electrical problems like this are often mechanical. In other words something visible and easily fixed, once found. I would start at the brake switch and follow the wiring into the bike. Careful disconnect every connection, clean and make sure it is tight and reconnect. Study the wires to see if the insulation is intact.

Best of luck!

 

Are you sure a relay is clicking? My 85 doesn't have a relay other than the starter relay. That sound may be a circuit breaker tripping. Sounds like you have a short (bare wire) or a bad breaker.

 

Yes, your right it is a circuit breaker tripping!! For some reason had relay in my head, so the surch begins!!! Anyone know of an easy way to find a short, or is it just the prosses of elimination thing!!

 

With a circuit breaker tripping you could try a replacement. If that also trips, then you have a search on your hands! Electrical problems like this are usually mechanical, in other words something visible, such as a loose connector, broken or chafed wire, poor ground. Just work your way along the wiring from the circuit breaker, checking as you go. Pull every connector apart, dismantle every ground, clean grease and refit.

Best of luck!

 

when the last time you had a tank off ? headlight open ? rear fender/ tail light off/opened If any of these thats where I would start looking also double any & all grounds pull them & clean under neith then dirt/rust can build up

 

Yeah, you have a short in the brake light circuit. Look under the rear fender and where the wires come through the fender. The MoCo just ran the wires through a hole in the fender without even using a grommet. Start on one end and work your way to the other. That is, start at the tail light and work to the brake switches or vice-verse.