Alternator Issues

[Jagalag]

I just replaced my battery. The old one was a Die hard gold, and I don't know how many years it was in the car, but I took it to Auto zone and got a new battery. The same problem I had with the old battery is still showing up with the new one. When I have the car stopped at a light, and the blower motor is on full, it changes speeds ever so slightly when I tap on the gas to get moving. I got the guys at Deathzone Autoparts to test the alternator output,
and they said it was only putting out about 50 amps, compared to the stock 80 that it should. Could there be a short somewhere, and is there a better way of testing the alternator, than just clamping that lead around the wire that they do?

[toyomoho]

A diode in the alternator may have failed. It is possible for the system to put out less then full current if damaged. Also check the battery cables, altenator current goes directly to the battery.

[sickwilly]

Its at 62% of its original output, according to autozone. Is that not your answer, especially under load--heavy demand because of heater fan? I am missing something here.

[tlwills]

Your alternator will vary it's output depending on the need. With no accessories on and a fully charged battery, the output will be minimum. With lights on high beam, heater fan on high, rear window defoger on and CD player a blazin and a low battery, it will put out close to maximum.