My 95 Chrysler Cirrus RPM gauge and radio is acting up.?

The RPM gauge works seldom and my CD/radio (factory) first was going in and out of stereo mode (like speakers engage them disengage to a single mono sound coming from dash speakers). I recently had my car door swung open and now the radio doesnt receive any power at all. I have checked the fuse inside the car interior and it was working. Before it completely went out (powerless) whenever I opened and closed my driver door Id have limited function of radio (either it would sound right or sound like weasels were singing - when closed the music went straight high pitched and would return to normal stereo when I opened the door. I have had alternator checked - no problem. No clue - please master mechanic help!!!!!!!!!!!