My voltmeter has started acting differently since installing a new alternator. I put in a 75 amp instead of the stock one. The car does have underdrive pulleys. I never had this problem prior to installing the alternator. The alternator did charge the battery. I took it on the highway twice for about 20 minutes each way, and it started this morning when I came out. It seems that at idle the voltage reads 12, and comes up to 14 immediately upon acceleration. Also, turning on the heater, flashers, lights, etc. make it go down where before it wasn't even noticeable (with the exception of the heater). After reading a bit, I know the first place to start will be to get a meter on it, and second to pull it and have it tested to see if it's defective, but does anyone have any idea what could be causing this? Could the alternator going have taken out the voltage regulator? Thanks