AC compressor noise??

[R Dubya]

Any of you guys ever turn down your radio when driving through town and able to hear the ac compressor?  I am getting a sound from mine only when its engaged.  Kind of a weird situation, it happened with the last reman compressor I put on, which did the same thing only a bit louder.  I am a little concerned its going to implode in the system.  I am wondering if this is common issue with these particular cars or if there may be something wrong with this compressor.

The alternator charge warning light comes on from time to time, but I know the alternator is charging, I am wondering if maybe the belt is causing an issue, or if it is possible the tensioner not gripping properly and possibly causing this noise with the ac on?  Any experience from anyone?

[TGPilot]

Is it a squealing noise or like a muffled clatter clatter clatter noise? Both my TSTE and TGP make the latter noise when it has been running for a while.

[R Dubya]

its more of a hum or vibration, but everything is tightened down properly and it holds its charge just fine, so its not low on oil or anything.  It makes that sound from idle to about 3000 rpm or a little higher.  I also don't have a working radio in the car right now so I hear everything too, but honestly I don't think it should be making that sound.  I would take a sound clip from inside the car, which is really the only place you can hear it, but it is too much of a droning sound and probably wouldnt record well.  I am going to test and see if the belt is slipping or possible the tensioner is bad, I will post back my findings in the next few days.

[pontiac6ksteawd]

The hum is quite common. I have yet to drive a gen 1 MPFI car that didnt make that noise.. My TGP makes it, My 6000 makes it, and about 8 other GM cars of this era make the same noise. If it aint broke, dont fix it,,

[R Dubya]

well there's something thats not right as the alternator light comes on from time to time, so something is slipping or the alternator is bad.  I will find out in a little bit, I'm going to take it and have the charging system tested to see if the belt is bad or what.  I'll get it nice and hot and take it down, will post the results in a while.

[R Dubya]

Well I fired it up and took it over to Advance this morning to have the alternator checked, and it seems to be running fine.  Here are some of the stats though, maybe I am wrong and should consider a replacement due to the light occasionally coming on.  The volts maintained a straight 12.6 or higher, which I assume is right on, and the amps hovered around 10-12 when idling.  When I kicked on the compressor however the amps dropped way down below 5 and for the most part stayed there, peaking once at 7.1 (according to their machine), but for the most part stayed between 4.5 and 6.  Is that bad?

The peak output was 64.2 amps, and from my understanding the stock alternator is rated at 105 peak power.  Do I need to consider a replacement alternator?  I know the noise is coming from the compressor and I may consider changing it out with a replacement j/y unit if I can find one suitable.  Any suggestions on tracking this noise from here?

[pontiac6ksteawd]

That alternator is shot. It should be maintaining a amperage of about 60-115 or more amps. The volts are also low, it should never drop to 12.5. Replace the alternator, and go from there.