Delco Bose failure - after everything was fixed...

[Matt B]

Boy, this Z really gives me a hard time... Haven't driven it for just one mile but already spent both, ages and a fortune into it...

This time I'm back to square one with my Delco Bose system. I recently had both, control head and CDM fixed by a company that is specialized on GM stuff and has a very good reputation. Front amps were fixed, too, rear ones replaced by donation parts. In the end everything worked well. Impressive sound for 30 years old!

But then... A few days later with the intention to enjoy some Michael Jackson 90s sound I switched on the radio and nothing happened. Control head went on, but antenna mast didn't come up and Bose remained off. I then followed all procedures, checked CTSY, Radio & WPR fuses and did my measurements at the Bose relay socket. Result: there is no voltage applied to the pink wire that comes from the CDM and should switch on Bose and Antenna.

Moreover, and this is even more strange, I recognized no mechanical noise coming from the control head. Neither CD nor Cassette player make any sound, as if they would not start. I can load and eject both trays with ease, but CD player does not show a track number or elapsed time. Also I can't fast forward or rewind the tape. So it seems to be more than just a switch trigger not working.

Car was not moved in the meantime and is always attached to a charger in maintenance mode.

Usually at this point I'd say "Pull it and have it fixed!" - but in this case that's what I just did. So, does anyone have another idea of a potential issue?
Anything that helps me to avoid pulling the CDM once more is more than appreciated...

[secondchance]

Matt,

I am not an electric engineer nor know much about electronics. Having said so, what you are telling us is that you have battery power, key on run position power (since you can load and eject CD and tape). does the radio come on?
I understand your frustration but most likely suspect is the head unit. why not call the outfit that serviced your head unit and CDM? Most likely they will suggest that you send back for testing.
I understand your desire to keep the car as was back in the day. However, I say restore and hold on to original radio but get yourself a current generation radio and use Metra harness and tap into Delco Bose amp/speakers. this way you are not changing out to 4 ohm system and reversion back would be less complex.
Just a thought...

[Matt B]

Thanks for these thoughts. Thing is that I'm SO close to have it work that I can't surrender now. I pulled the control head yesterday and surprisingly it worked when I switched it on one last time before unplugging it. Then I carefully squeezed it back into its slot and it stopped again. So I suspect an issue with the harness. I then pulled it again and as I could not find any evidence let it rest for a few hours and went for dinner. Again, when I returned it magically worked.
Next step I carefully put it back in place but used an improved technique to route the harness. So far everything works... Let's see for how long.

Aftermarket is a great chance but if I go down that road I'll install something really cool .

However next thing I will do is DRIVING my ZR. Sound system is second priority. There is this roaring engine and that transmission with its fantastically mechanical sound. Who needs more?