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Discussion Starter · #1 ·
I'm having a series of annoying electrical problems. Firstly it was my 7.5A brake light fuse that was constantly blowing (3 times a week). That stopped, now the rear driving light filament in the globe is blowing. The fuse for the turn signals/warning lights is also blowing constantly. I wiggled some wires and put a new fuse in for the turn signals and it lasted a while, but just blew again and now will blow as soon as I replace it and turn the ignition on. I'm pretty sure its a short, but I don't know how to trace it. I have a multimeter and a continuity tester, but I don't understand how wiggling wires around with the tester across the fuse slot is going to tell me anything. If I use the continuity tester with the ignition off, its always going to show nothing, and if I turn the ignition on its always going to show something, right? It says in the haynes manual to do the tests with the ignition off, but in that case a short will only show if its shorting the ignition (which its not since fuses only blow when I switch the bike on).
I'm pretty confused as to how I'm gonna trace this sucker. Any help or past experience will be much appreciated.
 

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If I use the continuity tester with the ignition off, its always going to show nothing, and if I turn the ignition on its always going to show something, right?
Wrong. Checking for current w multimeter in mode for that, ignition on.
What model & year?
 

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howley said:
I don't understand how wiggling wires around with the tester across the fuse slot is going to tell me anything.
What you want to do is put the continuity tester across the non-battery end of the fuse and the negative battery terminal. What you're looking for is an electrical connection to earth somewhere in between the fuse and the lights. If you can make the continuity tester light up (or beep or whatever) by wiggling the loom, you'll find the short.

The places I'd start looking are the bundle of wires that run past the headstock - the ones that move at one end with the bars, they rub against the frame as the bars turn and can eventually wear through, and around the seat - mainly the front edge - I've not had any problems there but I've hear from others that the frame near where the front of the seat clips down can also suffer worn insulation problems...

big
 

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Discussion Starter · #4 ·
I found that the wires coming from the alternator to the regulator were in bad shape around the connectors. Some metal was exposed. I don't think it could directly contact the frame (maybe it could), but I taped it up and nothing blew. This happened before when I wiggled some wires around, and it blew later on, so I'm not sure if its problem solved, but could the wires from the alternator have been the problem?

Greenmonster, its a '94 m900.
Big, that makes way more sense!

Thanks guys, keep it coming!
 
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