I drove my mustang into work today and on the way there I noticed that the volt gauge is going over the high mark and maxing itself out. It freaked me out at first but I got it into work and grabbed a volt meter. I checked the battery voltage and it was 13.84 Is that a good enough check or should I be checking right off the alternator? Because I thought it went alternator charges the battery and then the car pulls from the battery. Also, I checked it with the car running.

 

The alternator provides whatever the car demands and the excess charges the battery. If the alternator can't keep up with the demand, then the battery provides the balance.

If your hand-held voltmeter is known to be good and the reading at the battery (which is in parallel with the alternator) was 13.84 while the voltmeter in the car was reading high, then your ok. Just sounds like a bad meter in the dash.