Hi everyone, new to the forum after just buying my first MB

I just got a 2011 ML350 bluetec. I bought one of these: 7-way plugs and plugged it in but I don't get break lights working, and the pins don't seem to be in the configuration that the plug cap says they are. I tested it out with the vehicle in park, ignition on, but not with the engine running. I was wondering if maybe the truck has to be in drive or something else that might be affecting the lights.

The plug I bought is supposed to work with this truck (jcwhitney has an option to enter your vehicle make and model to check compatibility), but does anyone know if I bought the right/wrong one?

are there any other things that I'm missing that would be affecting the lights working properly?

thanks

 

im pretty sure the car needs to be programmed at the dealer for a trailer hitch.

 

Correct, the transmission is also reprogrammed as well.