I am now on my 3rd alternator.......

[Captain Mark]

.....in a week. I'll put a new (rebuilt) one in, and drive it for a couple of hours and the "GEN" light comes back on. This same thing has happened 3 times. So, obviously it is not my alternators having the problem....what's going on?

[JTY]

Hrmm. Have you tested your battery? What about your voltage regulator?

[Madcat455]

Did you have the auto parts store test the Alt before you did the replacement to be sure they were bad.

Also... Are they the factory style or the newer internaly regulated alts.

[Captain Mark]

Battery is fine......I'm suspecting the voltage regulator. I think I'll change it out and see what happens.

I did have one of the (new) bad ones tested, and it tested at 4 volts!

[benderbrew]

Captain Mark said:Battery is fine......I'm suspecting the voltage regulator. I think I'll change it out and see what happens.

I did have one of the (new) bad ones tested, and it tested at 4 volts!

Rare as it is, sometimes the wiring from the alternator has a very high resistance connection in the wiring somewhere. This connection maybe corroded, partially melted, or otherwise not correct. This type of high resistance connection causes the alternator to "overcharge" and subsequently fail. I've seen it once or twice. If the voltage regulator checks out O.K. check out the wiring from the alternator, making sure all connections are clean and tight. Another good indication is after you first start your car, put your hand on the alternator and see how hot it gets. If it gets very hot quickly, it's working overtime. Hope this helps.

Len

[Captain Mark]

Thanks Len, I will try that.

[Captain Mark]

Looks liek it was the voltage regulator. Changed it out and everything seems to be working fine. thanks for the help boys.