Main Fuse blowing again

[Robynn]

Recently replaced both the stator and the regulator rectifier on my '84 VT700 (my mechanic did it). Prior to that, we had determined that both were gone. Got the bike back and she's running pretty well. But, yesterday, I popped the clutch (yup, still relearning how to ride), and Petunia stalled and died. Tried to restart her, promptly lost all power, and had to replace the main fuse. Fortunately, I learned my lesson months ago, and had some with me. Boyfriend is however, concerned. We're thinking there's either a loose wire touching the frame someplace and blowing my main fuse, or we've got something that's going "bad" and it's pulling too much and blowing the fuse. To complicate things, bf looked at my fuel pump, and suspects it may not be doing well -- when he puts his hand on top, he can feel a tapping sensation -- he thinks that's not right.
Anyone with experience with this bike and what should be what? I really would like to start thinking about trips longer than 100 miles with a girlfriend, but BF is a little concerned that she and I will get stranded. (When I'm with him I always have a ride home on the back of his wing, LOL). Thanks in advance!
ride with, and

[Alan Naylor]

Well, if you're blowing a fuse it could be any number of electrical components. From the fuel pump having a loose wire, to something in the harness. I would stray toward a hard ground on the chasis somewhere, if it always blows the same fuse.

I had a problem where I couldn't maintain charge on a battery overnight. Turned out to be general degradation of the wiring and I had to replace practically the entire wire harness.

The easy way to look for a ground is to disconnect the battery and connect a multimeter set to resistance between the positive lead and the frame. Then just go through and jostle/wiggle the hell out of everything you can. When you get a resistance of a few ohms, you've found the general area of your problem.

Good luck! Intermittent faults are absoluteloy the worst.

[jpr1968]

If the fuse blew when you were cranking the motor I would highly suspect that the starter is going bad.

[Ramie]

Another thing to consider is if you've overloaded the circuit by adding any accesories that are run off the main fuse.

[John Hopkins]

Take a close look at the blown fuse..has the wire disintegrated into little balls or is it just broken..

Facts..

A fuse takes 1/3 of a second to blow and it doesn't blow until the current drawn is double the rating of the fuse..

so a 30amp fuse will have to draw 60amps for one third of a second to blow..An electric motor such as a starter or a fuel pump can get badly worn brushes or carbon build up in the commutator (rotor) and this can cause the type of problem you are experiencing..removing a motor and testing it across a battery with a large enough ammeter in line with it is one way but an ammeter capable of measuring 60amps is not cheap..it's better to strip the motors and examine them for obvious signs of wear..A local firm that does motor rewinds would be the best answer after all the electrics on your bike are 28 years old..not too bad really..The most obvious place to start is the starter motor..

John.