Tail Light fuse keep burning

[dtgates]

I have a 2004 R1150R with 40,500 miles. The tail light fuse keeps burning out (second fuse, 4 amp). Brake light still works (different circuit).

I had hyperlights installed and removed those. Fuse stills burns.

The R1150R has a front 5 watt parking light on the same circuit. I replaced the bulb and the fuse still burns.

There is difficult access to check the wires for a short. I can't find any noticable frayed wires. I also cut the factory over tightened zip ties around the wire harnesses near the sterring neck.

There is one other person on the R1150R.net who has been dealing with this problem for 2+ years now and has yet to find the solution.

Has anyone here had the same problem?
Any ideas?

Thanks...
Doug

 

[MotorradMike]

Does the fuse blow instantly when you power the bike or does it hold for a while and then blow?

 

[dtgates]

Does the fuse blow instantly when you power the bike or does it hold for a while and then blow?

It holds for a little while, maybe 10-20 miles?

 

[BUDDINGGEEZER]

I do not have a R bike, but I did have a K100LT. The smallest amp fuse in the K bike was 7.5 amp. Is it possible that the 4amp is too small?

To find a short in the wiring harness is:

1. Take a self resetting circuit breaker, attach a wire to each of the 2 terminals and insert the wires into each side of the circuit blowing the fuse. As this circuit breaker resets itself it will make a magnetic field.

2. Take a compass and slowly drag it along the wiring harness. the resetting of the CB will cause the compass needle to fluctuate. When the needle quits fluctuating, you are in the general area of the short.

3. Unwrap the wiring harness tape in this area to find the short.

Ralph Sims

 

[dtgates]

I do not have a R bike, but I did have a K100LT. The smallest amp fuse in the K bike was 7.5 amp. Is it possible that the 4amp is too small?

Ralph Sims

Thanks Ralph.
The circuit uses a 4 amp fuse. Those are hard to find.

 

[MotorradMike]

Here's another idea.

Since the wiring after the fuse goes fore and aft, there may be 2 wires coming out of the fuse connector on the load side.
It's a bit drastic but you could cut one of the wires and thereby isolate it to one load.

 

[bmwmick]

Doug,
Look closely at the wires for the instrument lights. There were several failures early on the R1100R bikes in that area. The circuit wasn't fused on the early bikes and a lot of wiring harness were replaced after the short.