Riding along, everything working great.(was fine a minute ago) Looked down, zero volts, bike still running fine. no horn, no turn signals. I hit the 'flash' on the dimmer sw, and the volt meter came up to where it belonged, turn sig. worked, horn worked too, as it should. If I just put the hi-beam on, none of the other stuff worked as on lo-beam. I suspect a ground problem, I cleaned all the plugs and connectors I could find, nothing changed. I had recently changed the timing chain, at friends' urging, as I am over 100K miles, BTW, it is a 1991 R100RT. I neglected to eliminate the rubber mounts on the diode board, I hope that is not what failed, but that is where I am going next, I guess.
I am confident that the rubber diode board mounts are in no way related to your electrical fault. The advantage of solid mounts is to facilitate heat transfer from the diode board to the rest of the motor. If your diode board has been heat damaged, it would not cause a fault as you describe.
Here is a clue; on every airhead I have ever owned, (all earlier than '91) the flash to pass high beam position on the left hand set is wired directly from an un-switched source. You can determine if your bike is wired this way by pressing flash-to-pass function with the key off. Light or no light?, A or not A? Proceed from there.
former Airmarshal, IL.
Thank you, 8053. I will check it out tomorrow. Long as I have owned this bike, I have never blown a fuse, I am wondering where they are! I do not recall seeing them anywhere on it!
I am guessing then, it could just be a bad connection on a fuse, and the power if back-feeding the rest of the things.
Mr. 8053 brings up some interesting points. If the items work when the headlamp flash-to-pass button is depressed, then your issue must be on the supply side (positive), rather than the return side (ground). Depressing that button simply brings power into the LH handlebar cluster from an alternate source.
Time to find those fuses !! 😛
Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.
The 1988 R100RS that I used to own had the electrical components under the fuel tank mounted on the frame back bone. I mention this because I would be looking at the headlight relay or starter relay, or their connections. I am going to guess that the fuses are under the seat or tool tray some where.
I never had an issue with fuses on an airhead except the instance where I had pinched a wire on the rear brake light switch when I installed a side car sub-frame on a /7. Obviously that was a self-created problem with a straight line between cause and effect.
Best of luck and keep us updated on your progress.
former Airmarshal, IL.
YES! You guys nailed it! I had quite a time finding that little fuse box, hiding under the X member on the frame, in front of the battery, almost under the tank! It didn't help that I had a strap wrapped around that area for the rear connector for my tank bag I use on long rides. The aluminum strip was slightly corroded, I bet it is original, from 1990 or 91.
I ordered the solid mounts for my diode board anyways, as I knew one of the rubber mounted ones is twisted already, and I am fixing to ride her to pick up my son's remains from Kingman, Az, where he was murdered 2years ago. Just one other thing to not worry about on a 2180 mile ride. I am going to try and earn my Iron Butt patch while I am at it. Thanks for the help!
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