2002 GMC Envoy rear suspension compresser

the front and rear suspension use the same compressor. when the air system fails the rear suspension will set a lot lower due to the front suspension being much stiffer to support the motor assembly..the air suspension compressor assembly for the base Envoy is behind the right rear wheelwell, on the frame well. For the XL Envoy it will be on the left rear frame rail near the spare tire. To test it, run a direct hot wire from a 12v supply (i.e. car battery) and the compressor should run.