2000 Grand Prix weird problem

I have 2000 GP...I get hiss from the radio speakers..but if I turn the heater or A/C on it goes away..Im at a loss...Thx for anyhelp

Is it more of a hissing sound or a static type sound and do you hear it in all speakers?

What happens when you turn the rear window defogger on?

its a hiss, and the rear defroster doesnt change it..it sounds like all speakers

Do you have cheap spark plug wires installed?

Sometimes I get static in my speakers even with the radio turned off.

Good point, do you have the Bose system? Maybe the amp is on the way out....

sorry tblake...been working alot...my wires are factory yet..one thing I noticed..it seems to be something with heater/AC...it seems its on all the time..the sound dissappears..if I press the knob...but comes back on within a few seconds