I just had my AC compressor changed for the 2nd time and now I have another problem with either the compressor or the Alternator....

There's a grinding under the hood that occurs under throttle increases and remains constant when the AC is turned on...Now, it could be the compressor again or the alternator from the added load caused by the AC. My volt meter took a huge dive when the AC was turned on and then quickly rebouded....

Any ideas???

My engine sounds terrible with the AC on. I think it's normal, since the AC has to draw alot of power and make the engine work harder.

what happened to the first compressor?what was the voltage reading with the a/c on?does it make that noise when the a/c is off?im thinking its the compressor for the noise since you say it only does it when its on.voltage will drop when the a/c is turned on which is normal unless its really taking alot of juice.