I just replaced my wagons head unit with a cheap Sony I picked up refurbished for $100. It blends nicely with the car, not to flashy. I bought a harness and antenna adapter at a local audio shop and wired it up, the problem is that the amp doesn't seam to be turning on .-. I have to crack the radio to full blast before I hear the slightest sound from the speakers :/ any ideas, suggestions? Also where is the amp located on the wagon?

 

There's a lot of useful information in the Electronics/Audio forum for this site, but here's a couple of tips --

Was everything working fine before you installed the Sony? If yes, then maybe the Sony has a problem. Maybe install the Sony in another car to test. Next thing to check is the patch cable. You need to compare the pinout for the MB harness with the pinout on the Sony radio. A quick check is to go to Crutchfield, input your car and see if the Sony is compatible. Or you may have an impedance mismatch.

The issue may be the antenna. If you had a good signal before the Sony install then maybe the antenna adapter you bought is bad. If not then maybe the antenna feedline or inline amplifier is bad or has a bad connection. Amp is located in Pillar C left side.

If you have the BOSE system the amp and CD changer are on the right side of the cargo area opposite the spare tire.

 

checked with Crutchfield the closest radio (Mex-BT2900) is compatible. So i doubt i would have problems with a Mex-BT2700 so for now i am going to check the stereo itself before taking a crack at the amp (its the non-bose). The connections are fine lets just see if the stereo doesnt have any defects... thanks alot Richard.

 

Is the volume low on all sources or just the radio? If it happens with CDs and aux sources, it's not the antenna.

 

Let me check, wow i need to buy a cd i havent used thoughs in a while XD
and it cant be the HU because i went and exchanged it just to be sure because it was a refurb. from the sony outlets... thanks vividracing

 

Well I still didnt try a cd but I tried the Bluetooth audio and I get the same results:/

 

was your factory radio a bose unit?

and just a heads up... depending on the harness adapter you purchased, you may need to swap the red and yellow wires as a few harnesses have them backwards.

 

Nope the harness is good and i don't have bose .-.

 

i just put in a new headunit and started with no bose as well.... didn't have any problems with audio though, just the harness issue.

maybe it's something to do with the speaker impedance on the oem speakers?

 

Maybe.. does anyone know where I can get the Mercedes harness diagram?