So I have a 1999 suburban with a strange issue. The radio works intermittently. I figured it was the radio so i bought a new one...worked fine for 5 minutes and now it does the same thing. it "seems" to be heat related. if the heat is on it seems to quit sooner...go to cool it will snap on and off. i am mainly referring to the sound...the radio actually always is on so i tend to believe it is not the radio itself.
Did GM put some relay or circuit thing inline of the speaker wires? it is strange because it is all the speakers at once either on or off...most of the time "off" sound-wise.
again the radio is new and it is repeating what the stock radio did so i believe it is the body of the vehicle somewhere but the radio is always showing "on" just no sound.
all the connections of the new radio install were done by soldering and heat shrink so i believe no issue there...but something is "up" between the radio and the speakers.

anyone else have an issue like this and figure it out?
i hate the idea of pulling all new speaker wires!

 

I'd suspect the power feed to the radio. Run jumpers for power and ground from the connector and monitor with the radio on and see if you lose 12V when the radio quits.

 

The radio always stay on..it is just the sound that cuts out.
are you talking radio power or 12volts in the speaker wires?
i do not think it is a high tech system such that it has a remote amp that could be acting up...but maybe it does. thats kind of how it acts but i just dont imaagine it has an amp. it is all stock so no aftermarket amp would have been installed. Did they come with amps back in 99?

 

You have 2 power feeds to the radio. A constant 12 volt and a 12 volt that comes on with the ignition switch. Check to see if you lose the constant 12 volt when the sound goes away.

 

I'm having a similar problem with the radio in a 97 Suburban that I recently bought. The radio or disk will play fine for 30-40 minutes and then there is a "pop" sound through the speakers and the radio unit goes dark, with no sound. A minute to a few minutes later, the radio unit comes back on and resumes playing, but the clock is reset to 1:00. This happens with both radio use and disk play. The on and off repeats. But, after the vehicle sits overnight or for a few hours, it will play for 30-40 minutes again before the first "pop" and power outage. Does this also sound like one of the two 12V feeds being interrupted? How do I identify the 12V feed to monitor? Thanks, Ed