banshee squealing on 89 200

[WLAMB@denver.echobay.com]

     Hi Guys:
     
     My '89 200 has taken to big time squealing upon startup and first
     couple of minutes.  I have checked all the belt tensions
     and they seem reasonable.  The noise sounds like the air
     conditioner compressor.  However, I can not toggle it off
     always by turning off the climate control.  It happens
     on turns too sometimes or from startup at a stoplight.
     
     All new belts were installed this past spring including
     timing.  Any thoughts on what is squealing?  I have listened
     with the hood up numerous times trying to sort out the source.
     Is this the failure mode for ac compressor bearings?
     
     Thanks in advance for your help.
     
     Bill