lost my alternator

[desert1]

My alternator burned out the other day, just made it home on battery power . I have a spare alternator and regulator as well but before I replace it I need some advice on where alternators usually short out is there an area of the wiring to look for? The only wires cooked on the bike are the coil wires in the alternator everything else is fine, any advice appreciated.
Bruce Doucette
78xs1100

[DGXSER]

Bruce,

It is not very likely the actual alternator is the problem. It is much more common that it would be the connector from the alternator to the harness. That connector is behind the plate the fuse block mount sto under the right side cover. So pull the cover, and then the three screws mounting the fuse block to the battery box. Pull that plate aside and you will see three connectors, one has three large white wires. See if it is melted, or very corroded. Clean.repair it as needed.

Next item would be the regulator/rectifier. I'd check it as well before you pronounce the alternator itself to be dead.

[TopCatGr58]

Hey Bruce,

Long time no hear, glad to see you've thawed out!

There's also diagnostic tests that you can do at those 3 white wires at the plugs behind the fuse panel, to see if the alt wires have actually shorted or not. The field coils can also get damaged especially if the rotor isn't properly centered, and rubs on the wires, but you said there were no signs of wear!

As DGxser said, it's more likely that the Reg/Rect took a dump. Some other tests for the field coils can be done to determine that it's generating a magnetic field.

I think it was Scott/3Phase that posted a while back about grounding a wire from the red/rect plug that will send FULL power to the field coils, and you can then test the charging rate, if it's UP to 14 or so, then that can confirm that the reg/rect is fried.

If you didn't already have a spare set, I'd suggest you look at my recent thread "Alternative Alternator Options" especially if you wanted to get more electrical power to run things like heated grips, heated vest, GPS, etc.! I'll get around to making the formal tech tip soon, but am still ROAD TESTING it, will be attending XSEast next weekend, and want to be able to report many hundreds of miles on the mod WITHOUT failure or fatigue!

T.C.