I don't keep the wiring diagrams at home, but I will try to help.
There is a mat in the rear trunk, take it out. Under there toward the front of the car, there is a black cover with a few plastic nuts holding it down. Take it off and you will see a large bundle of wires and some room to install the controller. This is where all of the wiring can be done. You will have to get the colors, for I don't have them with me.
The pulses are negative to lock and unlock. Only on the earlier cars did you need the alternating polarity.
ASE CERTIFIED MASTER AUTO TECHNICIAN
MERCEDES SPECIALIST 11 YRS