Bad Alternator?

[Overboost]

Originally Posted by Fifty150hs

Check the voltage output when the car is running. If it is at least 13.7 volts, it's not your alternator. If it's not your alternator, it's probably parasitic drain. Something isn't going to sleep. The telematic unit is the most common culprit.

Another caveat is some theories out there is when the alternator fails, it kills that telematic unit. I suffered a alternator failure and soon after the parasitic drain coming from the common failed telematic unit occurred.

I went to the dealer for my 140 amp alternator. It was expensive but I replaced it nearly 10 years ago and have never had a problem since.