Help !!Bike dead blowing main fuse.

[bultaco59]

Hello everyone, yesterday got the bike running and everything working, today bike dead
blowing main fuse, everything looks to be in order, no wires out of place,nothing burnt
dead short somewhere !! ok where do I start to track down this short, the bike was
almost done,f%$#&* me, six months of work and now this. need some help, something to go by, where to start, what to look for,most common failures in electrical
system. Any help would be great.
thanks
bob in burbank

 

[gggGary]

what year?

 

[buzzword]

try the hillbilly method: get a stack of fuses, start removing plugs and light bulbs one at a time, watch for smoke, and keep going until it keeps running and not blowing the fuse.

or, someone else here can probably tell you a smart way to do it with a ohms-capable multimeter.

 

[bultaco59]

Thank you for responding, my bike is 81, turn key on fuse blows,only main all others OK.

 

[angus67]

Look for wires that look "squiggly". Over heated, but not burnt. Kinda curly. Dig?

 

[retiredgentleman]

Remove the 3 other fuses, and the taillight bulbs. Install a new main 20 amp fuse.
Leave kill switch at OFF.

Turn on key..............install 2 taillight bulbs................install headlight fuse...
..................install signals fuse....................install ignition fuse.

It will likely blow the fuse after one of the above, which will tell you where to look further.

 

[bultaco59]

Good Morning everybody,just wanted to say thanks for all the help with problem
as it turns out I found the problem in the taillight one of the hots was grounding
on the fender,repaired wire, good as new, bike back on track.
Thanks Again
Bob in Burbank

PS Heres why I was pissed.