Blowing headlight fuse

I've been blowing a lot of headlight fuses lately. Has anyone else had this problem and what did you do to fix it?

I can't say that I have heard of this being a common problem. I would start looking at the areas that might have been removed or some other work done. Other wise you might have to start looking at probable areas like below the steering column and just following the wiring from the fuse to the lights. Let us know so we can all benefit. Howard

Back tracking from the Lo beam hot wire (White) the circuit goes to the Dimmer switch. The Dimmer is fed by the Blue/White (Bu/W) wire which comes from the headlight interrupt switch on the Starter Switch. The interrupt switch is fed by Black/Red (Bl/R) wire which comes from the headlight fuse and also connects with the Lo Beam Relay and exits the relay as the White wire.

I hope I got that right. Sounds a bit confusing to me too. So check the Dimmer switch, the Interrupt switch function of the Starter Switch and do a continuity check from the Bl/R wire at the fuse block forward to the W wire at the headlight terminal. Pay particular attention to the wiring from the handlebar switches and where that wiring may come in contact with the steering stem when the handle bars move.

I hope this helps. Please let us know how you get on with this problem. We all benefit from feedback.

Tim

something shorting out usually, look at the loom for wear/tears in insulation, even evidence of rubbing may be worth a closer look

About the only cause of fuse failure would be a short circuit to ground between the fuse's output end and the bulb. Wire chafing or a problem with the bulb socket would be the first things to check out as already mentioned. Use an Ohmmeter connected across a good ground and the output end of the removed fuse. Watch the meter for any drops in resistance when pulling and pushing on the wire harness between the fuse and the headlamp. If all is well the Ohmmeter should show a solid infinite resistance indication. If you see the needle drop or fluctuate it's an indication that the wiring is chafed against something. Then it's just a job to go over the wiring harness looking for damage from wear.


One other check would be to disconnect the headlamp fuse, disconnect the headlamp socket from the bulb and connect an Ohmmeter across one of the hot leads and the ground lead on the socket. Then take the bike on a test ride an watch to see if the Ohmmeter shows any drop in resistance. Riding on a rough surface would help here. Testing this way would show any chafing due to road vibration.