The other night I noted that the head lights were dim and the instrument panel light very low. I measured the battery and it was around 12 volts with the car running. Shouldn't the voltage be around 14 volts with the car running due to the alternator charging the battery?

I also expected the battery voltage to increase and head lights to get brighter with and increase in engine RPMs. The voltage and the brightness of the head lights did not change with RPMs.

Is my alternator bad?

 

That alt. could be going bad.Also does the battery light come on very dim?

The regulator/brushes could be worn and need to be replaced.Look on the back of the Alt.There is a peice that is held in with 2 phillips screws that is it.