Recap:
--------------- The other day the car started fine, we drove about 20 minutes, and then electrical devices started failing: first the speedometer, then the air conditioner fan, the windows were slow, and after another 15 minutes the car died (while driving on the highway) and the battery was too low to start. There had been no previous problems.
---------------
We got the car back from the dealership after replacing the battery. They said the battery wasn't putting out enough current, but the alternator tested okay. At first it ran fine, but now it's having problems again. It's been hesistating when stepping on the gas, the windows have been going slow sometimes, and the check engine light came on. The problems are intermittant though. My GF also said that it seems to behave better when the AC is off (note: she didn't test the fan and compressor separately).
Any ideas? I'd like to have a better idea of what could be wrong before we take it to the dealer again, especially since the problems are intermittant, and they obviously didn't find the real problem the first time. Does this still sound like it could be the alternator belt?
thanks in advance for any help,
-paul