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...