I have a 04 B300 I put a JVC CD player in and when I turn on the key the deck comes on with no sound but when I turn the headlights on then turn the dimmer all the way up then all the way down the sound works fine also if I skip to the next track the sound turns off untill I move the dimmer up and down again. The dash lights only work with the dimmer all the way up. Any imput would be helpful because it dont make sense.....
thankyou

 

did you use a wire harness? or did you splice wires?

 

there are 3 grounds that chould run into your stereo factory harness all joined into one point One of these grounds runs back to your computer if you perhaps snipped this wire out of the equation it could spell out your problems.

 

What did you connect the Light blue with Red stripe wire to. This wire is used to supply voltage to the audio unit only when you turn the lights on. Most aftermarket decks do not even use this wire as they are lit up all the time. Try disconnecting this wire from your deck and see what happens.