Just put in a new 650 amp battery two days ago and last night it died while I was driving home from work. Jumped it, drove a mile and it died again. Jumped it, drove another mile or so and it died again. Jumped it a third time, got it into the driveway and was able to shut it off.

Went into the auto parts store and had them test the alternator, it passed on all checks, but it turns out the battery is a 63 amp battery out of a 72 Monte Carlo. Now, I got some new battery cables and a ground cable and I'm hoping if I swap those out I'll start getting some power from the alternator again.

Thoughts? Help?

 

When the car is runnung the power is coming from the alternator and also keeping the battery charged at the same time. When your car is shutting down is because you drained the battery of its power and the alternator is NOT working. I think your problem is the Alternator on its last legs even if it checked ok..

 

I concur!

Also check the new alt when you buy it, have it tested.
Bought 1 from napa, installed it, didnt work, did this 3 times till i got one that finally worked!

 

Well they tested it..I saw in the store that all of the ratings were right where they needed to be so how does that make sense that the alternator is going out?

 

yeah it happened to me it was the battery then kept doing the same problem and it was my vats if you have vats i suggest you check it.

 

If it is 1988 model it did not have the VAT system.

Now back to the Alternator problem, It did check OK at the store. Well the only advice I can give you now is I hope you have AAA, because that alternator will be going out.
So you can wait on the side of the road until they come and get you. Been there and had it happen, It would charge fro a while until it went completely.

 

So what you are all telling me is: just get a new alternator from the actual year of my car?

 

Yes, 105 amp one would be best.

 

You guys never mentioned one thing: THE wires in the car need to be thoroughly checked out. It could be that the power isnt provided because he has a bad ground. I had gone through some problems "assuming" the wiring is good in a car. The grounds can and do rust out raising resistance and blocking needed power. Just thought it might help.