94 S500 W140 Radio Issue

[larracfb]

Had some a/c work done on my car (evap change) which involved going under the dash. Somehow, the radio got messed up. When I turn on the radio it switches to "PHONE". I tried to disconnect the phone and today, I replaced the radio with a like unit but to no avail. Radio is a Becker. HELP!!!

[Limited Edition]

I've heard of that before but I don't remember how to fix it. I think there is a wire that mutes the radio when the phone is on and you have to cut power to this wire and then the radio functions again. Hope that helps a little.

[larracfb]

I will try that. Thanks.

[larracfb]

Originally Posted by Limited Edition

I've heard of that before but I don't remember how to fix it. I think there is a wire that mutes the radio when the phone is on and you have to cut power to this wire and then the radio functions again. Hope that helps a little.

Ok, got the schematic, located the wire (yellow/blk) coming out of terminal A3 behind the radio. Insulated the terminal, and voila, it worked! That wire was previously disconnected from the telephone end. Obviously there's a short from the radio end. Insulating the radio terminal fixed this. I dare not go further into the wiring system to look for the "short" as it might turn out to be a nightmare!LOL!

Thanks for the tip.