Help With Chevy Tahoe

That's okay that's what's supposed to happen.  All it takes is one shorted speaker, and the head unit goes into protect mode and shuts down all the amplification, for all the channels--usually.  If the shorted speaker is the front left, all of the speakers should go out, although in some vehicles the two rear speaker would still be playing--it would just shut down the front left and front right amplified channels.  make sense?

I had this happen to me with a jeep cherokee one time, and it ended up being an exposed wire inside the black rubber wiring "boot" that covers the wires as they pass from the door jamb to the door.  a little piece of electrical tape to cover up the exposed part, and it was good to go.  hopefully it's that simple for you...

It's also possibly that it's a loose connection, but the short is more likely since more wires could short than power wires could be loose... but maybe someone put like a noise suppressor on and made a crappy connection or something.