Our 2005 Dodge Sprinter has the rear A/C. When I turn on the rear A/C sometimes there is a loud noise from the engine compartment, it sounds terrible, like a loud low-toned screech. I can feel it in the engine too when the rear A/C is switched on while driving. I'm guessing there is a compressor for the rear A/C and that it is seizing up or there is something wrong with the clutch. Does anyone know if that would be a correct assessment? Also what is the part number for the rear A/C compressor and is this something I can handle doing myself? The work I have done on the Sprinter has pretty much been maintenance related (front and rear brake pads, oil changes, fuel filter changes) but I have done some more difficult work on other vehicles (converted a '94 Mustang GT from an automatic transmission to a manual transmission).