alt going crazy

** Looking at my battery monitor my alt was acting crazy** Amps were all over the place* charging 50amps* drawing 20 amps voltage* 15 down 12.8** So I tightened the belt* no difference* The alt positive cable connects at the positive terminal at the starter*** Pulled the cabled off the starter polished with a likkle scotch brite** now every back to normal** Interesting the terminals did not look that dirty* Lesson learned

The first thing I would do is to move the alternator cable off the starter and connect it directly to your battery bank. Chuck

I think we are all guilty of this a number of times. *Low voltage battery circuits hide dirty connectors and switches very well.*

I had a simular problem with my port side alternator, except it wouldn't charge at all. Took the alternator off and had it tested, checked out fine. I finally swapped the alternators port and starboard and it worked fine on starboard engine. *Cleaned battery terminals and checked the whole circuit out with a volt meter all the way to the alternator. *Everything looked good but the alternator still wouldn't throw a charge.

Connecter and post at the starter looked good, but I cleaned it anyway and now the alternator works. *Moral of the story; just because you can see 12 volts on a volt meter, doesn't mean the connection is capable of passing enough current to excite the alternator.


-- Edited by Edelweiss on Monday 11th of July 2011 08:36:16 PM

Funny the voltage on the volt meter was at times reading higher then normal but the amps on the battery monitor was all over the place but you have love an easy cheap fix