I bought my son a Magellan NAV with the reverse camera option to put into his C240 MY03. We have the camera mounted and tried tying into the rear light harness with black to the brown wire and red to the Grey/Blue wire (I found another thread that identified it as the reverse light).

With this configuration the car is giving a malfunction error. This was something that I was worried about having happen but had hoped if I was simply splicing into the tail light wires it shouldn't be a problem.

Can anyone tell me how to get past this?

 

The car monitors the current flowing to the lamps and uses that value to determine an open, shorted, or incorrect lamp.

The easiest solution is to install a relay near the rear fuse block. The relay will draw minimal current and take power from the rear fuse block for the camera system.

The expensive but easy option is to install a trailer towing module that has a reverse light function.

Call a trailer hitch installer near you, perhaps they can help.

 

Thanks Moviela,

I ended up trying something a little different. It seamed odd that the simple approach I took would not work but I understand the current flowing approach. What I did made this that much stranger. I applied the wire right to the metal circuit of the light mounting bracket (not sure how to describe the grey plastic panel that holds the lamps) and there was no malfunction recorded. Now the wires are soldered to that grid and all is good.

As best I can tell, the draw on the wire was to much but there is such a large contact on the circuit metal that it is not a problem.

 

you can go to your local car audio specialist, they have bypass cords and harnesses or they could order them