No AC from generator - GT750L

[holysmoke]

Hi,

Sorry I haven't been on in a while. Hope everyone is well. Life in Arizona is good. I have a quick question.

Charging to the battery has died. I don't seem to get any AC to the rectifier. Measured resistance of the alternator coils, close to short, looks good. Measured across the rotor pick-ups, 10 ohms, as expected. Everything looks like it should give AC. Verified resistances of stator and rotor at the connections to the rectifier. Any clues on what could cause this?

Thanks,
Ron

[Buffalo-guy]

Ron.
There are two things you could check, if you haven't. Check each yellow field wire for resistance to ground. Should be infinite. If any of the three show continuity to ground, then your stator is done. Also, you could check if your brushes are intact, with the flexible lead in the mount housing actually attached to the brush. I got caught on that one once.
It's been a while since I've been on board as well. I do lurk from time to time, just to keep up.
If you are in Tucson, then I wasn't too far away from you this spring. Had a great ride on my re-built Strom with a few other folks, through the Arizona desert, and got as far as Safford, where we turned back north. You must be familiar with the "Coronado Trail". That's about the best motorcycle friendly road I've been on yet. Reminds me of what I've heard about the Dragon's Tail on this forum, only the darned thing is 80 miles long. Two of the guys got on the throttle, and scrubbed their front tires off, one down to the cord,... in 80 miles. Absolutely fantastic road, and magnificent scenery, and we had to ourselves. Here I go rambling again. The guys around here are sick of hearing me shoot off about that ride. Now it's your turn.
Good luck with the charging system, and if you haven't already done so, install an new style fuse holder, and save yourself some future grief . Experience talking here. Cheers.
Fred

[jabcb]

As buffalo-guy suggested, check the brushes & stator.

See wiring diagram topic for wiring diagram: viewtopic.php?f=29&t=4743

The voltage regulator powers the rotor. If the voltage regulator doesn't power the rotor, then you won't get any AC from the stator.

Check the connector for the voltage regulator to make sure its clean & you have good connection. With bike on but not running, check the voltage of the green wire at the connector. Should get close to battery voltage.

[holysmoke]

Buffalo Guy, sorry I missed you on your way through Tucson. And you're right, the Coronado trail is great. I took that on my iron butt ride.

Great input about the regulator powering the rotor. I have a newer regulator from the company up in Oregon, the name escapes me for the moment. I just assumed that the alternator just generated its own ac and didn't require a feed voltage. That changes the possibility of the failure. I'll check the voltage on the green wire, and check the stator windings to ground, and check the connection of the brushes.

Thanks guys,
Ron

[holysmoke]

Mystery solved. The Oregon regulator has failed. I confirmed that I have 10 ohms green wire to ground. Can a faulty battery take out the regulator? It holds a charge, but I noticed that when I put it on my trickle charger that it never stops charging like my other battery does.

Ron