Ok.... there is no MUTE on the deck.... only the steering wheel.
Do we know (or suspect) that the Mute button works on a change in electricity going thru it and not a "punch" on/off button.

Also, is there normally a "time limit" on MUTE, or anything like that?
If someone could try it, and wait like 5mins to see if the music automatically comes back on or not. It'* always done it for me... I figured it was a 5min timer, or after a song ends or something weird like that. But like I said, now it'* only staying muted for like 5-15 seconds.

I would... but ever since I swapped my HU my controlls don't work... :( I can try it on my dad'* GP tomorrow night if that helps... same delco deck...

Does it vary with speed, or distance? The buttons don't click on and off, they are only momentary. Maybe a button is bad, and is shorting, etc causing the mute function to go again.

The steering-wheel buttons are a ladder resistor arrangement. That is, you have one wire in, one wire out, and as many buttons as you want bridging those wires, but each button has a different resistance value. Thus when you push a button, the stereo looks at the voltage (or resistance, or whatever) of the completed circuit to figure out which button you pressed.

No, it'* a push-on/push-off configuration. However, it can also be cancelled by one of several _other_ actions, such as inserting or ejecting a tape or CD, turning the unit off and on again, or changing the volume up or down. It may be that your Mute setting is getting cancelled by something else: a flaky steering-wheel button or front-panel button on the stereo, among other things.

And just for the record, on my '93 factory ETR with CD, pressing the Volume **** on the stereo acts as a Mute, as well as the Mute button on the steering wheel. I think that'* a common setup on many (but not all) GM units.

More recently though, I belive that GM has opted to use the volume **** for on and off.... Do you have a yellow or oragange button to power the radio off?

Yes, it'* the older style with the separate power button.

Ok... while I was stuck in traffic today I decided to do some "Testing" to see if I can pickout anything... here'* what I found.

Pressed the mute button... music came back on 36 seconds later.
Pressed the mute again.... music came back on 3mins 21 seconds later.

Pressed the mute again, music came back on 5mins 10 seconds later BUT.... it came on exactly when my dash lights turned OFF (DRL lights came on... it got sunny) So a change in electricity due to DRL'* coming on.

Pressed the mute again, waited 12mins, did not turn off.

Adjusting volume or changing bands/stations would normally turn the mute off. I'm betting you have a flaky connection on one of the other functions, the volume up or down in particular. It might pay to take the steering wheel apart and clean the boards/connections.

How does one get the wheel apart?

There are two srews in the back... I don't know if you use those to remove it or not, but be careful working around the airbag... you don't want that to deploy in your face.