My son has a 2000 Stratus, with 2.0l and auto transmission. A week ago, he was driving on the freeway and the car just dies on him. Only a clicking noise when turning the ignition key. Had it towed home and we jump started it and it ran fine. We removed the jumper cables and it died. I reason that the alternator was toast. I charged the battery all night and the next evening I replaced the alternator and drive belt. Car starts right up and runs fine for about 3-4 days, then it leaves him stranded again. I jump started it and charged it with my truck for about 10 minutes and he was able to drive home. I charged the battery and took it to have it tested. Results were battery is okay and fully charged. I double checked the alternator connections and hooked my voltmeter up to the jump start terminals under the hood.

With the key off, the battery reads 14v, when running, it reads 13.5v, which as I recall is about right. So it looks good to me. Tonight, he gets stranded again and I had to charge his battery for about 30 minutes and he was able to make it the 15 miles back home.

It looks to me like the alternator is not doing its job, even though my volt meter says otherwise.

This is really puzzling. I hate to just throw a bunch of money at this, because the car is old, but he is not in a position to buy a new car right now and I am trying to help him out.

Can anyone point me in the right direction? Thanks in advance.

 

The battery should read 12v when off, and closer to 14 (14.4 ideal, but things like A/C, defrost, radio, lights will bring this down a little).

I would check the ground wires connecting the battery and the alternator to the frame. If you've got a bad or corroded ground, it may not be able to move the amperage needed to charge the battery. There may also be a short somewhere that's quickly draining the battery faster than the alternator can charge it.

Did they just test the battery voltage, or did they do a stress test? It may still be 12v, but much less amperage than it should have (and therefore need replaced).

 

I believe they load tested the battery, it took about 5 minutes.

I'll check the ground wires this evening.

Thank you.

 

My son took the car to an auto parts store and they tested the charging system. They told him the battery was good but the voltage regulator was bad.

As I understand it, the voltage regulator is part of the ECM? The alternator I installed has a label on it stating "Externally regulated".

So I guess I need to look for a new ECM. Anybody know where to get a reman unit? I hate to gamble with one from a salvage yard.

Checked the resistance on both + and - battery cables, and they are fine at 0 ohms. ECM plugs are tight, and the pins were clean.

 

Bump.