hissing noise . a/c compressor?

[thepewterpooter]

I have a 2002 GMC sierra 5.3l and it started making almost a hissing noise. I thought it was the power steering pump but took it somewhere and they said it sounded like a a/c compressor. anyone know how to determine or what can be done?

[Doug_Scott]

You need to provide more information. The a/c can be turned off easily to see if the noise is coming from there. Set the HVAC mode control to floor, temp to hot, if the compressor indicator light is lit up on the fan speed switch, press the button in to turn it off, and set fan to off.

A/C should not be running now, is noise still there?