magic smoke

[graybird78]

been having issues with charging system all year. went for 60 mile ride last nite. got home shut bike off,to open garage. bike fired up no headlight no dash lights. thought bad connection at relay. tapped relay it worked. go to work this morning, bike running ,shut garage door ,turn around to see thick smoke from under tank. shut off bike pushed in garage. came home tonite took tank off to find somekind of resister had gotten hot and melted wiring. so what are your opinions.charging system is charging,verified with dvom. time to find different wiring loom.

[TopCatGr58]

Hey Greybird,

The RESISTOR you're talking about is probably the BALLAST RESISTOR that sits under the left side of the frame/under the tank...it does get hot and so it usually mounted there to allow the airflow to help cool it a bit..but if some wires got loose and layed up against it, then it could have gotten hot enough to melt them! Just ensure the BR is away from the rest of the wiring, repair the melted wiring..and you should be good to go. The wires that got damaged may have been the ones to the headlight relay.

T.C.

[graybird78]

t.c. the resisiter im talking about is in the wiring harness on the right side of bike.its tapped up in the wiring harness. looks like it goes to a white wire in the harness.i have the headlight relay bypassed for now . lights all work again. drives me crazy when i know what happened ,but dont know why. iknow it got hot ,but why.

[3Phase]

Graybird,

That'd be the Headlight Relay diode that lost it's magic purple smoke. It's like a one-way check valve for electric current and the diode is supposed to take the A/C signal on one of the three White wires from the alternator and turn it into pulsed D/C to turn on the Headlight relay. It's a diode/check valve so it also stops current from flowing back into the Stator from the Headlight relay until the Ignition is turned off.

There's a short somewhere (duh!) and it baked the diode or the diode baked. Whatever happened, the diode stopped being a diode and turned into a fancy wire with a funny looking bump in it, then it burned up when the current flowed back through it from the Headlight relay to the Stator.

You can replace the diode with one from Radio Shack but you should find out if there are any other electrical shorts or you'll just let the smoke out of the new diode too.

.