I've got a short somewhere...

[Guest]

Well, the bike is running great now. Unfortunately I have a short somewhere. The fuse for the blinkers and brake light keeps blowing. My headlight and running light still work though. Any thoughts on where/what I should look for? I know its a short, I'm just not sure where quite yet...

[tom203]

Well, the bike is running great now. Unfortunately I have a short somewhere. The fuse for the blinkers and brake light keeps blowing. My headlight and running light still work though. Any thoughts on where/what I should look for? I know its a short, I'm just not sure where quite yet...

Will just triggering the brakes trip the fuse? By now you should have scooped a wiring diagram off Basscliff's- the headlight has its own fuse and I don't know what you mean by "running light".

[Steve]

If it blows when you apply the brakes or the blinkers, look for your short after the appropriate switch.

If it happens when you turn the key ON (or, at least, before applying brakes or blinkers), look for it between the fuse and the switch.

Most-likely cause is a wire that is rubbing against the frame and has rubbed through the insulation. Look around the steering neck where the wires move a lot, and along the frame, to make sure the wires are not riding on the frame gussets, where they will rub on the edges of the gusset.

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[DrunkenChekhov]

Thanks a lot guys, I'll start looking there tomorrow. It happens just when I turn the key "ON" before I apply the blinkers or brakes, and doing so doesn't cause a spike in voltage.

What I mean by running light is how your brake light is on all the time, and gets brighter once the brakes are applied. The first part of that works for me (the "all the time light") but not the brake-"heyI'mslowingdown" light.


Random question that I don't know if its related. On my front turn signals, the right is a dual filament bulb and housing, but the left is a single filament bulb and housing. That can't be normal...

[OldVet66]

Some bikes had running lights on the front turn signals. Someone has mixed the sockets. I would make sure it is wired for single filament use and that it's not the source of your short. Its simple wiring, a common ground return with a feed for each filament. You see some strange wiring on some of these bikes where people cob things together.

[cowboyup3371]

If you are referring to your taillight then yea, you could have exposed wiring that's rubbing on your fender.

[koolaid_kid]

On the bulb with a single filament, remove it and look into the socket. It should have two contacts. If it has one contact it is a rear unit. The fronts function as running lights as well as turn indicators. The rears function only as turn indicators, hence only one filament is needed. You might be able to force a single filament bulb into a dual filament socket, but it would be very difficult. The configuration of the little stubs is different on each type bulb.

[OldVet66]

You can use a dual filament bulb as a single, just try each filament lead to see which brightness matches the other turn signal the closest, abandoned and cap the other lead. I would put it on your list to change one of the sockets later to match and use the one the bike had originally. PS, the single filament bulb will have one center contact for the feed, the socket shell is ground, the double has two bottom contact points, socket shell is still ground.

[tom203]

What I mean by running light is how your brake light is on all the time, and gets brighter once the brakes are applied. The first part of that works for me (the "all the time light") but not the brake-"heyI'mslowingdown" light.


Random question that I don't know if its related. On my front turn signals, the right is a dual filament bulb and housing, but the left is a single filament bulb and housing. That can't be normal...

Does this bike have two bulbs in tailight or just one (my bike has one)? It's likely someone switched to non stock front right turn signal, so make sure that they didn't wire it up wrong.

[OldVet66]

Tail light has to be dual filament, (it's possible there are multiple bulbs but not usually) running light and brake light. It's possible that you will find your short when you straighten it out, someone didn't know what they were doing, or the brake light switch isn't adjusted correctly or working.

[FLHGSRay]

Years ago I learned about trick for finding shorts in electrical wires. Have never tested it myself. Replace the fuse with a 2 prong flasher with jumper wires attached. Turn on the circuit and the flasher will start clicking off/on, (it's trying to blow), allowing you time to search for the short. Then follow the suspected wires with a compass and the needle will start to jump when you near the short. Thought I might get to try it today on the HD, but I found the short in my headlight by sight. 2 wires going to headlight rubbed against a sheet metal bracket behind the fairing. Ruined a good ride last Friday night. Lost both beams and the spotlights. Had to rush back home before dark. If anyone tries this trick, and it works, let me know.

[Redman]

Years ago I learned about trick for finding shorts in electrical wires. Have never tested it myself. Replace the fuse with a 2 prong flasher with jumper wires attached. Turn on the circuit and the flasher will start clicking off/on, (it's trying to blow), allowing you time to search for the short. .....

Can do pretty much the same by replaceing the fuse with a light bulb (like a spare turn signal bulb). Solder wires to the light bulb (or have a bulb socket) and somehow connect the wires to the fuse holder (maybe solder wires to a already blown fuse). Then all the current that would be going thru the short to ground and blowing the fuse will have to go thru the light bulb and do nothing other than light the bulb (the light bulb will limit the current to what ever the light wattage bulb is, 3/4th amp for 8 watt bulb for example). Wiggle things around or remove devices from the circuit untill the light goes dimmer (and other lights come on some). Have done this for troubleshooting industrial electrcail controls for years.

Dave

[Redman]

.... It happens just when I turn the key "ON" before I apply the blinkers or brakes, and ...
......

Look on schematic and see if the horn is on that circuit whos fuse blows.

Keep in mind that power goes to the horn(s) all the time so an internal problem in a horn could blow fuse as soon as turn on key, even before hit the horn button. (the horn button does not switch on the power. Power is to the horn all the time. Then a wire goes from the horn to the button, THen the button completes the ground).

Weiter you understand that or not, try disconnecting the horn(s) and see if fuse blows again or not.

Dave Redman

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[tom203]

Look on schematic and see if the horn is on that circuit whos fuse blows.

Keep in mind that power goes to the horn(s) all the time so an internal problem in a horn could blow fuse as soon as turn on key,

Weiter you understand that or not, try disconnecting the horn(s) and see if fuse blows again or not.

Dave Redman

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Yes, the horn is on same circuit and hot feed down to it could be chafed against frame,,, but he said his brake light was sorta working and it too is on same circuit unless PO has gone creative with wiring.

[DrunkenChekhov]

Well, I have yet to find a wire that has rubbed through its insulation, and I'll be looking more indepth into the turn signals and horn tomorrow. There is one thing I forgot to add though, I put a 20 amp fuse in to see if that would make any difference, but it just blew a different fuse. Does that mean the problem could be with my fuse box?

Electrical really isn't my thing...