Turn signals kill bike

[Cbguy]

Hello out there, I have a 71 cb750 that has run seamlessly for years. I have been riding without issue for the last 2 months since the weather has gotten nice. I had just started my ride home and signaled my turn and the bike died instantly. I was able to start the bike right back up and ride. But as soon as I signaled again it died. I got home and put it on the center stand and tried to do it again but it didn't seem to work. I also have the high beams in when I ride. I did a no no this winter and left the battery hooked up but all I really noticed was some build up on the terminals.

My only guess is it might be my harness going bad, the battery measured 13-14 volts when idling. It is the same battery from the winter I topped off the water with distilled and it charged right up. Any thoughts would be greatly appreciated.

 

[jpdevol]

As the fuse did not blow it may not be a short or excess draw in the signal system. My first suspicion is that a condition existed wherein the the additional ~50watts of signaling load dropped the voltage available at the coils below a threshold to produce good spark (~11VDC). To test for that, test voltage at the coils and compare to voltage at the battery. A healthy system will show about half a volt difference. A system with poor connections may have 1.5VDC of voltage drop. Add that to a weak battery or marginal charging and the system is on thin ice. So, if you're driving along at battery voltage of 12.8 on 50W hi-beam, hit the brake (25W) and hit the signal (46W) all of a sudden the coils might see less than 11VDC and you lose spark. Test it & let us know