Head Unit Powers but No Sound Comes from Speakers

[baseball07]

Hi, I have a 94 Mercedes C220 that has a Pioneer deh-1200mp head unit installed in it. The head unit powers up just fine, but there is no sound coming out of the speakers (I bought the car with it like this, previous owner said it worked at one point). I checked all the fuses related to the radio system in the car, the fuse on the back of the head unit and tested the "pico amp" fuse on the Pioneer head unit and they are all fine. I tested this by checking conductivity between the metal around the RCA jack and the chasis of the head unit and it conducts. I am sort of out of ideas at this point.

Here are my wiring connections, I am about to just buy a new head unit with the though that the amp in the head unit went bad. Can someone give me more suggestions? Is there a reset or setting on the head unit preventing it from sending sound to the speakers?

Pioneer Out MB Wire

Black Brown

Red Purple/Red

Yellow Pink/Yellow

Green Blue/Red

Blue/White Blue/White

Green/Black Blue/Red with Brown dots

White Black

White/Black Brown/Black

Gray Yellow

Gray/Black Yellow/Brown

Purple Green/Red

Purple/Black Green/Red with brown dots

Click to read more...

 

[basswiigee]

may have a blown amp on hu.... unhook the wires from everything except power and ground, then get a little speaker home speaker or any speaker and start connecting to the speaker wires and see if you get any sound... thats a pretty old hu, and pretty basic, i'd probably just get the new hu, the upgrade from that 1200mp is only like 69.99 lol, but seriously, if you can't get sound out of the hu, just get a new one... or see if you can borrow one and see if you get output from there... also you can look up your cars wiring diagram and see if its hooked up right but if it worked once upon a time... the hu old it probably just blew....

 

[baseball07]

That was my thought, I checked all the wiring and it looks ok. I'm not a car audio guru so I am not sure if I am missing something or not...

 

[baseball07]

Anyone know the output transistor component on this, or have a schematic?

 

[Side Show 10+ year member]

are there even speakers in the car? are they hooked up? has it got a factory amp? is the headunit faded to the rear but only connected to front speakerS? could be many things

 

[Side Show 10+ year member]

also, not worth fixing IMO....