1992 Lincoln Continental Stereo System Not Working Properly

I have a 1992 Lincoln Continental Signature Series with the cassette deck/head unit, accessory CD player below, and the factory amp/JBL speakers. The CD player never worked, as in no display, wouldn't even pull a CD into the deck, the most it's ever done is light up the trim when the headlights are on.

The stereo worked fine when the car was first purchased, after that it started losing the audio and coming back on after cycling the power repeatedly, finally the audio just went dead. Today, I removed the CD player and was surprised to hear the audio return, reconnecting the CD player causes it to fail again, so I've just removed it for good.

The problem is that the amp doesn't seem to be working now and the head unit isn't going to push those JBLs by itself. I've taken a multimeter to the amp and it is getting power, so I'm lead to believe that the CD player might have been responsible for triggering the amp on. I've searched for wiring schematics to try and force the amp on with no luck. Am I on the right track or am I just barking up the wrong tree?

Thanks in advance!