Wiring Adapter to Connect Vehicle 4-Pole to Trailer 6-Pole

Question:

My trailer has a 6 pin male connector but my truck only has a 4 pin female What products do you have to make this work.

asked by: Brian

Helpful Expert Reply:

We do offer adapters to allow you to connect a truck with a 4-pole flat trailer harness to a trailer with a 6-pole connector. These and other formats for trailer wiring are shown in the linked article.

Note that there are two types of 6-pole connectors, the round type as on Mighty Cord # A10-6034VP and Hopkins # 37175, and the square type as found on Jayco trailers, for which you'd use # 30104.

The 4-pole connector on your truck carries only stop, turn and tail light signals. The trailer's 6-pole has these functions and others too, typically a trailer brake circuit and a 12V trailer power circuit. If you want to make those other functions active you'll need to make additional connections using the pigtail leads on the adapter. Otherwise only the lighting functions on the trailer will operate.

For example, if you use # A10-6034VP you'd use the blue wire to connect to a trailer brake controller like the Prodigy P2 # 90885 and the black wire to connect to the tow vehicle's battery through a circuit breaker like # PK54540.

6-pole round connectors can be wired with the center pin either as brakes or 12V power, so you'll want to test your trailer using a 12V battery to determine what function on the trailer is carried by each pin. You can refer to the linked article on trailer wiring for guidance.