Converting 4-Pole on 2008 Chevy Express to 4-Pole and 7-Way That Can Be Used Simultaneously

Question:

I have installed part number 31345 onto my 2008 Chevy express van. Your video was very helpful, thank you. With that part you end up with a 4 pin plug. I would like to have access to a 7 pin and a four pin. I was looking at part number HM40975. My question is how do I wire the back so both ports work?

asked by: Jeremy C

Expert Reply:

Both the 7-way and the 4-pole of the # HM40975 are wired so they'll be active at the same time, but the doors or flaps that cover the plugs are designed in such a way that it's physically impossible to open both at the same time. You can use one or the other, but not both.

You can easily install a 7-way, but how you'll proceed will depend on whether or not the trailers you'll be towing have electric brakes or not. If the trailers have brakes, you'll need to install a brake controller using our Brake Controller Installation Kit, part # ETBC7. The Tekonsha Prodigy P2 brake controller, aprt # 90885 would be an excellent choice. The controller is easy to use, and is highly rated by our customers. The ETBC7 kit includes an adapter that would plug into the 4 pole provided by the # 31345 you've already installed, with 4 remaining wires that would need to be connected. The entire installation procedure is outlined in the instructions for the ETBC7 kit that I've linked for you.

If the trailer doesn't have brakes, the adapter included in the kit mentioned above is sold separately as part # 37185. The adapter would plug into the 4-pole, you'd ground the white wire to the vehicle and the remaining wires can be tucked up out of the way. The adapter provides both a 7-way and a 4-pole.