I installed a z120bt with PAC OS4, PAC SWI-PS, and XM, in my 2008 Tahoe LT2 with standard audio config.

 

Recently I was informed that no sound is coming from my second row door speakers. In addition I noticed that my driver door speaker sometimes work and sometimes doesn't. The driver door speaker does not cut in or out but sometimes works when you turn the truck on and other times not.

 

I did the install myself, so I would like to think that it is not a wiring issue. Could it be anything else before I go ripping the dash open and testing all the connections?

I have a Z110bt and I have a similar issue, but my speaker outputs don't work at all. Only RCA outs work. Ever since I bought the radio. I always had an amp. So i never even tried the speaker outputs. I'm down sizing and tried to reconnect it to the factory speaker outs and nothing. I know the wiring is good. I made an 8 wire harness from the amp in the trunk back up to behind the radio to the factory plug. I tried resetting the radio and restoring factory settings but no luck.

 

Does anyone have any ideas or is the unit no good?