If you unplugged the changer that could be at least part of your problem since the output of the radio (dash) is routed thru the changer and then to the tuner (trunk) part. If you want to remove the changer you must pull apart the cable and plug into the tuner. The right angle connector from the front plugs into the tuner. when installing it goes the reverse cable from CD tuner jack goes to tuner, cable removed from tuner is plugged into extension and goes to frontgerat on CD
The whole setup is unique, the changer is no longer available the radio and CD can be rebuilt by Becker