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Electrical Problem, 93 Fatboy

Knuckles

Member
Riding the bike last night, and all of a sudden I lost all power while at highway speeds. The engine shut down and I lost all lights. The only light that was staying on was the oil light, but it was real dim. After taking off the dash panel I found a few loose connections on the ignition switch. Got her started back up rode about two miles and she did the same thing. After sitting a few minutes she would start up and run. Got her home and I replaced the ignition switch(had a new one laying around). Rode the bike today, after riding about ten or so minutes, the problem reoccured. Iam going to go thru the wiring on the bike. Any Ideas?
 
Do you have the factory wiring schematic for the bike. Have you made any electrical mods to the system.

I have no idea if back in '93 self resettable Circuit Breakers were used, but since the problem clears itself in a given period of time, it sure sounds like a bad CB. A Bad fuse holder can also do somewhat of the same thing.

If you do have the prints for the bike, see if there are any CB's in any of the heavy current power feed wires.

The fact the oil light still glows with every else dead does throw a curve ball into the picture. That part makes no sense to me.
 
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Yes, I have a shop manual, and as far as I know there has been nothing done to the wiring. The bike only does it when she warms up. Possible faulty circuit breaker?
 
1) You have the manual. Great
2) No one has hacked the wiring. Great

First determine if your bike even has resettable Circuit breakers. Take a look at the prints and locate the Battery. My guess is that off the battery or off the ignition switch you may find either some fuses or CB's. Does the print only show Fuses or is there a mix of fuses and maybe a couple of CB's.
 
There was problems with the breakers back in that era. I would just replace the breaker. I had a 90 that did the same thing, there was a recall on them.
 
Ok this is embarassing but oh well. So I replaced the main circuit breaker, it needed it the inside was pretty beat. But the problem still happened when I shook a wire harness. So I turned off the light in my garage, and noticed a sparking coming from the ignition coil area. The 12V ignition coil wire was loose, and hitting the engine cylinder, causing the bike to turn off. Repaired the wire and wrapped it in heat shrink. Now its good as new.

Thanks for all the info.
 
Good job finding the intermittant problem. The key was doing the simple things first, given the bikes age, and then old fashion gently flexing and tapping things with an insulated screw driver handle and patience. Add heat gun or cold spray if temperature related and plain old determination.
 
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