Electrical question
 

The factory fader switch in my 420sel seems to be bad these days beacuse I get no sound from the speakers when I start the car unless I= unplug the fader switch and plug it back in. Yesterday I was driving with the radio on but no sound was produced, but when I pressed the sunroof switch to lower the sunroof,the sound went on. I have noticed that ocasionally if I use some switches like the sunroof and power seats it will make the speakers work. Does that indicate a bad fader switch or some kind of short circuit somewhere?

i would try a new fader switch but it sounds like the speaker ground[s] have been compromised.they should remain above the vehicle chassis but sounds like one may have rubbed thru.this prob causes a speaker protection device to come on and who knows what the parameters for it going off are.it's poss i suppose for the bad circuit play to be happening in the fader switch.

Hhmmm. Where exactly are the speaker grounds?

two wires going to each speaker,one is ground ,usually the wire without the stripe on it.

Thanks. I will take a look at them.