On my 1991 C4 auto coupe, on the right (passenger) side of the "real" radio receiver (original equipment Bose Gold) there are 4 opening for pre-configured wiring plugs; however, I can only locate/identify 3 (the 2 on the left and the one on the lower right, looking at it from the right hand side mounted).

It seems there should be something that goes in to the "upper right" corner female plug on the receiver -- can anyone help?

Appreciate all the help from you experts out there, thanks!!!

I assume you are working in the system. Can you share the rest of the story?

It's been a long time since I was in there... I will have to check my 92 Helm manual...

moving to audio.

The upper right opening is empty! If I recall correctly, the other 3 plugs are white, black and blue.

That's what I was thinking, though it now pretty much confirms my theory that I have all the wiring back together, but with no sound I probably have all 4 amps blown in the speakers :-(

Thanks

Is the antenna plugged in? Did you check the fuses?

Yep, antenna is plugged in (although it only goes up partway, I have another post about that problem!), and all fuses are OK, the tape doesn't work either, I get nothing from any of the speakers, but a strange "hissing" sound from the control head unit (not receiver)...I'm thinking that could be bad too?

Quote:

My 85 bose had a speaker relay that had to receive power from the headunit, and it would let power flow to all the amps. You need to get a wiring diagram for your year to diagnose.

I've swapped out the relay with a known good one, still same problem, also there is 12+ volts at the orange/black plugs at each speaker. I would think this would indicate the relay is sending voltage to the amps at the speaker units, but the amps are not sending anything to the speakers...?

replaced the CDM ("real" receiver under the dash, not the head unit in the center console) and 4 amps on the speakers...got tunes now!

Cool, thanks for getting back to us.

I had a feeling the receiver was dead...