VQT

I changed the power mirror ECU yesterday. The mirrors work now. But my radio stop working. I can't turn it on/off, only one station is on and catches many station including TV stations. None of the buttons work. I finally got the the tape player to play but can't eject while it is playing, only when I turn off the engine that I can eject the tape out. The CD changers has power but I can't turn it on either.
I thought that I might of short some wires while taking the mirror ECU out. After checking the shop manual, I can't tell that I short anything.
Manual said to check between A3 and A4 to ground for continuity, if it is a short there. How am I suppose to trace the wires. The manual section for Radio seem to miss a lot of information and does not shows the wiring colors from each connector.
All fuses check out OK.
Has anyone came across this problem before?
Any help appreciated