Blowing ignition / horn fuse on 81 KZ 1000 CSR

Hello everyone,

It’s been quite a while since I posted here. Life and the fact that my 81 CSR has been running like a champ, that is until past weekend, just kept me in lurk mode. Any way, me and some mates were headed up to the Adirondacks for a long weekend of camping. The bike ran great on the ride from Cape Cod to North Chatham, NY where we spent our first night. The next day dawned grey and promised wet weather. We waited out the heaviest rain or so we thought, hitting the road around 1 pm. We did hit some heavy rain, but not even a hiccup from the bike. The rest of the ride to Fort Ticonderoga was damp, but no more rain fell. We stopped to take a few pictures of the water falls, and then hit the road again headed toward the camp grounds. About ¼ mile after starting up again, the bike just dies. I pull off all the gear and find the ignition / horn fuse was blown. We messed with the wiring, looking for a short, etc. until it got dark to no avail. Came back in the morning and spent the next few hours, tracking down fuses and trouble shooting with no luck. Every time we would get the bike running, start plugging things back in, the same fuse would continue to blow.

Reading the archives has lead me to find out the fuse block can go bad on these bikes, and as I could find no other reason for the problem, that’s where I’ll start once I find a trailer to borrow to get the bike back on island. I also found the excellent intermittent electrical fault diagnostic, so that should be a good place to start. I do have a factory service manual as well.

Sorry to be long winded, but wanted to provide as much info as I could. Any other ideas as to what could have gone wrong are greatly appreciated.

TIA,

John on the Vineyard
81 KZ 1000 CSR
77 XS 650
76 750 Bonneville

Sounds like the dreaded chafing wire rubbing metal somewhere in the harness problem....

does the clutch cable run near the horn?,,,if it does look for cracks in the rubber near the horn.it may be arcing across to the hot side of the horn. i had a similar prob on an old kz 400

Update

I pulled the wiring harness and an inspection found a dead short on the red right hand coil wire. Explains the blowing of the ignition fuse when the handlebars were turn to the left, there is just enough play in the harness to push this wire into the coil mounting bracket. I fixed the short and also rewired the three yellow alternator wires as they were brittle, with the insulation flaking off.

Good find! A piece of heat shrink should be able to cover up the insulation damage(if you can get it over the wires.

I wonder if the plastic brush on insulation would survive this situation.

The wire was brittle and because I had the harness off already, I opted for splicing the wire back together again.

If I had found the short on the ride when it occurred the shrink tubing or liquid insulation would have been an option just to get me home.