XTZ660 blowing fuses
 

My XTZ660 of '97 started this week blowing the main fuse. The strange thing is that as long as I don't switch on any lights there is no problem riding. When the lights are on without the engine running,no problem. Anyone has a wiring diagram of this bike? That should help me figure this out.

Hi
This sounds like a direct short to earth, you may want to look at the ignition switch as a starting point, i had a few problems along the same lines a few years ago, but have a good look for any damaged wires in the loom. Hope this is of some help. Skip

fixed it
 

Thanks Skip,
I have been working on this over the weekend, checking it out with a multitester and getting nowhere. I put in a separate fuse for the lights, so at least the engine keeps running. After trials and tribulations I found some cocons of bugs or insects inside the lightswitch, in the bottom part. There it made, now and then, a short between the earthcontact of the horn and the other positive contacts.I cleaned it out with a lot of contact spray and the problem is gone.