Plain 4-wire connector with 5-foot harness

Question:

Want to wire a car to tow a small trailer that has a flat 4-wire connector. Curt offers a 58044 that consists of four wires and a connector only. Curt also offers a 55560 that looks much the same as the 58044 PLUS the addition of a black box. What features does the black box provide? Will the 58044 harness provide lighting that works as well and the 55560? I know it’s possible because one is already installed in my car. I want to wire another car so that it will correctly power lights on the same small trailer with a four-wire connector. Both vehicles are 1998 VW Jettas. At etrailer.com, two wiring arrangements would seem to do the job. One is the Curt 58044, the other is the Curt 56175. Curt C58044 connector has four wires both in and out. The Curt C56175 has five wires to connect to the tow vehicle, a black box, and four wires to the trailer lights. What is the function of the black box the C56175 uses?

asked by: Clyde

Expert Reply:

The Curt # C56175 is a trailer wiring harness that includes a powered converter that is used to handle the additional strain that can occur when powering trailer lights. The # C56175 is the confirmed fit trailer lighting harness for the 1998 Volkswagen Jetta.

When a vehicle is connected to a trailer and the car is not specifically set-up for trailer towing from the factory, the powered convert will make sure that there will be enough power sent to the trailer to fully illuminate the trailer lights. According to the wiring manufacturers, your Jetta will need the converter, because the by itself the vehicle electrical system is too weak to run the extra lighting on the trailer.

It is possible to us the standard 4-flat harness, # C58044, but you will probably run into issues with having enough power to light the trailer lights.

I have attached an article that has more information on power converters and trailer wiring in general for you to review.

expert reply by: Jared P