No Sound from Stereo UNLESS YOU OPEN THE PASSENGER DOOR
I have an '05 C230 with the standard MB stereo; AM/FM/In dash CD/CDC in the glove box. After not driving my vehicle for almost 2 weeks, I got in and started it and the stereo wasn't outputting sound. The stereo was on and it allowed me to switch between CD, CDC and the stereo (although it didn't read the discs or attempt to). I was driving one of my daughter's friends home while contemplating what could have gone wrong, and when my daughter's friend opened the passenger door to exit, the sound came on. Later, back at my house, I started up the car and had no sound. I opened the passenger door and the sound returned. Any ideas? Thanks in advance!

A wire might be pinched when the door is closed cutting off the circut also it could be an exposed wire grounding out. Look around the door jam and see if you can see a crimped wire or one that has the covering removed and touching the body of the car. Those would be my first initial thoughts.
Sounds like a pinched wire to me that shorts when the door is closed




