How many miles is the stock alternator good for?

I now have 205k on the stocker and the guage is showing about 11-12 volts with slow flashers and dim lights.
It then jumped up to around 13-14 for a while then, fell back.

Napa says they have a new one-no core, in stock for $175.

What else could be causing low voltage?

 

Mine was a broken wire behind the windshield washer bottle along the inner fender well that lead to the ECM. This was after I bought a new alternator and ECM.

 

Any respective parts store will test the alt for you.

 

Been a few weeks.

Put some faith in Napa and they are as bad as Autozone, Checker, Western Auto, etc.

"Tested" the alternator and "Yep it's bad".

Bought and installed new one with same result.

I look at the sticky and find the ASD relay is a possibility; swapped with the a/c relay and no problems since.

So stock alternater was still good at 210,000 miles but brushes are almost to the limit. Might put it back on to see how long it will go.

 

Might as well, and return the NAPA one to them for a full refund.

 

I thought there was a no return policy in effect at NAPA on all electrical items.

 

Beats me, I never shop there.

 

Mine died around 220k.

The brushes were gone and the slip rings they were on were as well.

FWIW, it still tested good on the bench at 2 different parts stores. But put it onthe truck and it wouldn't charge.

 

The only time they do a return is if its deffective. They have a no return policy because people would just throw parts at a problem and if it did not fix it they would return it. If some other part was defective in the same system it could cause the part they repaced to burn out or damage it. I worked the counter in a parts store and alot of people just replace stuff instead of checking in to whats wrong. I had plenty of people buy a computer, then try to return it for a refund, and want there old one back. Sorry, no can do.

 

Yeah, I'm sure they don't return electrical items even though the old one tested by them was "bad" yet was good.