Blowing Fuses

[sebring38]

I am blowing the fuse that is on the circuit with turnsignals and brake light. I can start it up and let it idle and everything continues to work great. But if I take off down the street it will blow within a few minutes. What might it be, or, what's the best way to trouble shoot this when obviously it's not going to happen in my garage.
82 GS850Gv

[jpaul]

My forst guess would be a short. Sounds similar to the problem I had with my 1100E. Check all the connectors on the wiring harness, especially the ones with multiple wires. Be sure and pull back the rubber boots covering the connections far enough to check the wiring really well. Good luck, intermitent electrical problems are a first class b!tch to track down.

[SqDancerLynn1]

I would start by checking the bulbs

[sebring38]

The bulbs? They all seem to work ok. Why do you suggest that?
thanks,

[Billy_Oliver880]

I remember popping fuses left and right when my rectifier went out. Then the bike up and died. Maybe someone could back me up on this. See how many volts your charging system is putting out.

[SqDancerLynn1]

Sometimes the bulbs can come apart & still work The filiments could shortout to each other

[Redman]

Maybe it blows the fuse when bike hits a bump and moves a wiring harness somewhere. Maybe can recreate in the garage by pushing- pulling- wiggling on wiring harness, especially where wiring harness runs along or acrost some frame part. Wiggle one small portion at a time and check fuse before wiggling next small portion. Look for were insulation seems to be worn away by rubbing on frame or whatever.

[mixongw]

Try to sort out what is being used when you are riding that isn't used sitting still.

1. Gear indicator (all five)
2. Brake light switches (front and back)
3. Side stand switch


Maybe there is a short in one of these circuits.

[Road_Clam]

Re: Blowing Fuses

I am blowing the fuse that is on the circuit with turnsignals and brake light. I can start it up and let it idle and everything continues to work great. But if I take off down the street it will blow within a few minutes. What might it be, or, what's the best way to trouble shoot this when obviously it's not going to happen in my garage.
82 GS850Gv

You most likely have a chafed t/s hot wire grounding out. First thing you need to do is isolate which T/S or brake component is the problem. Does the fuse pop as soon as you place it in the fuse panel? If it does this means you have a short before the handelbar switch. If it pops a fuse as soon as you hit the t/s button its after the switch. Personally I have never seen a bulb be the cause of blowing fuses, but I suppose it could be the problem. Once you have an idea which t/s is shorting out, simply start disconnecting connectors until a fuse stays powered. Now you have a circut to follow, then its a matter of carefully inspecting the wire for the chafed spot. Good luck, be patient and systematic, its a PIA job (and uses many fuses in the process). Check the simple components first, check all bare unprotected visable wires for chafing.

[duaneage]

Start with a Volt-Ohm meter. set it to read low ohms, like 0-100 ohms. This method does not waste fuses.

Turn off the bike. Remove the red battery lead.

Remove the fues that is blowing. Connect the red lead from the meter to the fuse terminal that goes to the wiring in the bike ( not the terminal that comes from the battery)

Touch the black lead to the battery. If it reads 0 ohms you have the red lead on the wrong terminal, select the other one.

Next, connect the black led to the engine ground or the - battery terminal. Hold it on there or have a friend hold it.

Turn on the key to the on position and read how many ohms you have. Now start wiggling wires until it goes down, way down. Check the bulbs and the connectors. You'll find it .

Hook everything up again.

You could also check the current drain by connecting the red lead to the battery side of the fuse connector and the black lead to the other connector, selecting 0-10 Amps on the meter, and with the bike running check and see how much current it draws. But for that you need a meter capable of 10A to do that.

[sebring38]

Thanks, guys. excellent ideas. Gives me something to do this winter. Will get that old Radio Shack VOM out and blow the dust off.