Oldsmobile/Buick Repair: 88 Buick Regal 2.8L V6..., electric cooling fan, wheel bearing

Question
Hello Van,
My car has a pulsating hum from the rearend. I already have brand new calipers and brakes and e-brakes. I thought it was the wheel bearing, but it sounded like the noise was coming from the driver side so I changed it and drove it down the road. The same noise was there. Is it possible the sound transmitted from the passenger side? Also a sort of grinding noise sounds when I turn the A/C on at first, then disappears. Do you have an idea what this might be? Maybe the compressor clutch is engaging hard, but the A/C works fine. Thanks.

Answer
Hi Mike,
Sure, the noise could have been from the right side. Are you sure it isn't the fuel pump?
As for the compressor, not enough info for me to say from here. What you suggest is possible, or it could be inside the compressor.
If that car has an electric cooling fan that comes on when the A/C is on, it could be that.
Van