bing tracking image
Q & A Icon

What Is Needed To Pull A Trailer With Electric Brakes Using A 2016 Mercedes-Benz Metris?


I am looking for parts for a Mercedes Metris to tow a travel trailer. The trailer is around 4000lbs and has a 7 pin connection for electric brakes. I need the hitch, wiring kit and possibly a brake controller. Can you send me the products that will fit a Mercedes Metris please?


Expert Reply:

In order to tow a 4000lb trailer with your 2016 Mercedes-Benz Metris, you first need a hitch. I would go with the Curt Trailer Hitch Receiver Class III - 2" # C13276. This is the highest weight capacity hitch we offer and has a max tongue weight of 900lbs and max towing capacity of 6000lbs.

In order to get a 7-Way Plug-in on your Metris, you first need to install a 4 Pin trailer wiring kit if your vehicle does not already have one. I recommend going with the ZCI 4-Pole Flat Trailer Connector and Installation Kit # 119250KIT. This wiring kit does not require splicing into the factory taillight wiring as a lot of kits require, it instead clamps over the necessary wires.

Once a 4-Way is installed on your Metris, you will then need to install a 4-way to 7-way adapter kit. The Universal Installation Kit for Trailer Brake Controller 7-Way RV and 4-Way Flat # ETBC7 is a popular option. This will allow you to use 7-way or 4-way on the same adapter. You will plug this into the 4 way plug on your vehicle and then there will be a power and ground wire you will have to connect. There will also be a blue brake wire which will connect to the blue brake wire on the controller.

For the brake controller and wiring harness, I would go with the Brake EVN # TK63VR and Brake Control Plug-In Harness # 20127.

If you have the factory brake controller wiring which is usually under the dash (should be 4 wires), then you will simply wire the brake controller harness to the wires under the dash; you must use a circuit tester like the LCD Digital Circuit Tester # PTW2992 to test the function of each wire. The wire that has power ONLY when brakes are applied will attach to the red wire on the brake controller.

If you do NOT have the factory controller wiring under the dash, then you will need to install the Roadmaster Stop Light Switch Kit # RM-751475. This kit will connect to your brake pedal and then be wired to 12v and to the brake controller's red stoplight switch wire.

The brake controller wiring is as follows: White connects to negative battery terminal, Black connects to positive battery terminal, Blue connects to the blue brake wire coming from the trailer adapter, and red is the wire that connects to the Roadmaster stop light switch for the brake signal.

I have attached several demonstration/installation videos.

expert reply by:
Andrew N

Products Referenced in This Question

Product Page this Question was Asked From

Q & A Icon

Similar Expert Q&A Pages

See More Q&A Expert Answers >>