gnychis

I am looking for some basic guidance on trying to diagnose the problem with our E320. One day, we could not get the car to start. We could jump it, and it would go a couple miles, and then just sort of die off. The electronics would begin to turn off, and we would pull the car over and it would basically die. When trying to re-start the car, it would not start. Not even turn over. So, we thought the battery might need replaced. So, we replaced it, but still having the same problem.

If we jump it, it will not go very far before it dies. I am thinking this might be related to the alternator? Is there a chance that it is the voltage regulator? If so, it's worth the $60 chance to replace it and see how it goes. Is there any better way for me to diagnose this?

RobertG

Get a voltmeter and check the voltage at the battery with the engine running, it should be over 13 volts.
Charge the battery first before you check voltage with the eng. running.
If the battery is fully charged then it should start without jumping it.
If you have the same voltage at the battery with and without engine running then your alternator is not charging, replacing the regulator only might get it to charge.

GoldenPimp

Ah... you need a new battery?

DJTALLMO

Agree with RobbertG's process but from the sound of the symptoms, it sounds like your alternator. I had these identical symptoms in another, eh-hem german vehicle, and it turned out to be the alternator.