My 91 RS has the stock AM/FM Stereo w/cassette and four speakers.

About half of the time when I turn the radio on, there is a nasty static sound that drowns out the everything else. It doesn't seem to come from a specific speaker. It's across all stations. Sometimes it's very loud and sometimes it's more moderate. Turning the radio on/off doesn't have any effect.

I would appreciate suggestions on what to check.

 

Has this been a constant problem or one that just started?Loose grounds/harness connections can cause electrical interference,have you modified the ignition system also it could be the volume control.The contacts in them sometimes get dust/dirt in them.Use a good electrical contact cleaner and pray down inside the shaft.

 

All the electrial stuff is stock.

It started a few months ago and has gotten worse.

Good idea about checking all the grounds and the contact spray.

 

I would go over the entire system's length of wires from component to component. Hit all connections with contact cleaner (speaker connections, stereo controls, the connectors to the tape deck) and make sure that the wires aren't frayed anywhere.

 

the stereo system in my moms z28 started acting up, a few weeks later the coil went out. hows your ignition system look?

 

Coil's been in there for around four years. I've not looked at it in a long time. That's another good idea. I'll check that too.