Using 4-Pole to 7-Pole Connector for Wireless Brake Controller on 2010 Toyota Highlander

Question:

Im looking at renting a travel trailer with a wireless brake controller. My vehicle has a four pin connector. How do I convert to a 7 pin without the need for a hard wired brake controller? Looks like I ave to hook up a 12 v hot lead to the battery in some fashion.

asked by: Randy

Expert Reply:

Since you already have the 4-pin connector, you will need a 4-pole to 7-way adapter like part # 37185. You are correct in that you'll need to run a 12-V power wire from the adapter to the positive battery terminal. For that, you'll need a 40 amp circuit breaker such as # 9510 as well as a length of 10 gauge wire like # 10-1-1 (which is sold by the foot). The power wire is needed to supply the power module mounted on the trailer. The white wire with the ring terminal would be grounded to the vehicle frame. The other two wires are for trailer reverse lights and brake controller output. Since these won't be used, you can just tie them up out of the way.

I've included a photo to make things a bit clearer. I've also linked to an installation video of this adapter on a vehicle similar to yours, a 2012 Toyota Highlander.

expert reply by: Amber S