jrferguson

I have a 97 Ford F-150 that has a noise coming from the alternator area. The weird thing is that the noise only occurs when the AC compressor kicks in. I used the old rubber hose trick to confirm where the noise is loudest and it appears to be from the alternator area and not the AC area. I took the belt off and the alternator pulley appears to rotate freely and has no noticeable up/down play. The AC is way down to the bottom area of the engine while the alternator is right on top. What could this be?