ST 1100 electrical troubleshooting

[Darko]

Hi all - my first ever post...and slightly frustrated.
I own '92 ST with low mileage that has developed a charging problem. To make a long story short, initial stator resistance/continuity test, according to Honda Service Manual, checked good. The rectifier resistance test did not; Of all 30 possible readings listed in the service manual, NONE measured ANY resistance nor continuity (even the Honda dealer checked it and agreed that the rectifier is bad). Well I got a new one, and before I even installed it, I wanted to check the resistance test - just out of curiosity. I got the same lack of anything on my meter as the old, presumably "bad" rectifier...you can tell where this is going...So, I don't know why, but I re-did the stator resistance test again - This time, I am only gettting resistance across one pair of yellow leads, and absolutely nothing across the other two combinations. So, a week ago, the alternator seemed ok and the rectifier bad. Now, I am not confident that rectifier was bad, and could it be the alternator???
HELP please! ...any help?
"D"

[birdie_xx]

Not sure if this will help, but here you go...

http://www.electrosport.com/electrosport_fault_finding.html

BTW, I had a similiar problem on my XX. All readdings were o'kay, yet my battery was dying. I even took my RR to a friend and it run great on his bike.

I had to tke the stator out and check it visually.
It turned out there was a small burn on wires.

Replaced the stator and it's all good now.

You might also want to check this thread... http://www.st-owners.com/forums/showthread.php?t=3182

If you find your Alternator at fault, I would highly recommend you buy the newer one ('96 and up ! ).

Good luck....


P.S this happened after about 80K miles of use...

[wjbertrand]

This sounds like the classic 28A alternator failure. Historically, most of the failures have been with the stator and not with the regulator. It's very difficult to test the regulator because you must use EXACTLY the same meter model that is specified in the ST1100 service manual. I tried two different digital and one analog style meter and could get nothing but nonsense numbers from the regulator tests described in the manual. I've since loaned that regulator/rectifier out to others (I upgraded my ST1100 to the '96 and later 40A unit) and it has proved to be fully functional in spite of the goofy readings I was getting with my meter. When I took this to the dealer, they didn't have the right meter either and told me they just try a new one on the bike and see if that fixes the problem or not. They don't bother testing the old one.

My guess is that you have a failure, perhaps intermittent in the stator itself. Do any of the wires or connectors (3P or the one that plugs into the regulator) have the appearance of burning or experiencing overheating?

[Darko]

Thank you - the guide for troubleshooting is great - it gives me more information than the service manual is more user friendly.
I got the 40A alternator on order...
"D"