am I killing my alternator?

I had my original alternator fail on me recently and since then replaced it with a new/reman unit. I installed the new alternator and my car has been running fine since last thursday, but now today after I floored it through these S turns on the way over to a friends house...I happened to glance at my battery gauge and it was right about where the red area starts and my check gauges light came on :mad:. My car has been running right around 13.5 before I floored it.

Some "spirited" driving shouldn't hurt your alternator. Keep in mind that the voltmeter gauge on the dash isn't always 100% accurate. If you have access to a multimeter, you could measure the actual battery voltage across the terminals and compare.

Some "spirited" driving shouldn't hurt your alternator. Keep in mind that the voltmeter gauge on the dash isn't always 100% accurate. If you have access to a multimeter, you could measure the actual battery voltage across the terminals and compare.

Take his advice and report back.

Ive had "new" alts from autozone fail on me after a few months before. Even had to go through 3 reman alts to find one that actually put out what it was supposed to.

Wouldnt surprise me if it really did fail.

I measured 12.64 volts across the terminals with the car off and 11.85 with the car turned on and the voltage did not increase after that. I am going to remove the alternator and have autozone test it to see if it's any good...even though they tested it before I installed it and verified with me that it was good.

While you are taking the alternator to be bench tested, you ought to take the battery with as well and have them load test it. Also, make sure that all of your connections are clean and tight when you reassemble.