What's Killing My Alternators?
 

Folks, I've replaced my battery twice, and then the alternator 3 times in the last two months trying to resolve a dead battery issue, what a hassle! Twice the tow truck guys did a test and said alternator is bad.

I thought it was bad alternators I was buying, but I'm wondering if something ese was killing them, like a wiring issue?? I'm taking it to a real mechanic tomorrow!

96 Ram 1500,

Is it the alternator that is bad? Or is it the voltage regulator? VR is in the PCM......

The test meter both times showed the alternator as bad.

can a short, or missing ground cause this?? If not what else could?

Remember that I said this is the 3rd alternator that's gone bad over less then two months

Hey You what does this mean?

VR is in the PCM.

The tow truck driver likely just put a voltmeter on and determined it's not charging, That doesn't mean the alternator itself is bad, as HeyYou mentioned there is also a voltage regulator that controls the alternator. It is part of the PCM and a control wire runs from the PCM to the alternator. So it could indeed be a failure in the PCM but also simply a wiring issue.

There is a fuse in the pdc under the hood, If it's bad no output to the battery.

Yeah it was two diff tow truck guys (I had to get towed twice) and both times they used a voltmeter and another test device.

OK guys thanks again, I'm taking it in to the mechanic this morning.

what does PDC, and PCM mean?

PDC is Power distribution center. The fuse/relay box under the hood.

PCM is powertrain control module. The computer that runs the engine/trans (if you have an automatic)

Voltage regulator for the alternator is built into the PCM. Unfortunately, they are a common failure point. Change the alternator as often as you like, and it still won't charge, as the VR is toast.