Wiring Needed For a 2018 Toyota Highlander With 7-Way Only Wired For Trailer Lights

Question:

I bought a used 2018 Toyota Highlander which looks like it came with after-market hitch including a round 7 pin trailer electrical socket. I planned to pull a camper trailer that has trailer brakes but found that that socket didnt have any power coming out of the pin in the 1 oclock position. I then noticed the black wire thats connected to that pin wasnt connected to anything else. What wiring and fuse do I need to get that wire connected all the way to the battery as I understand is whats needed for that pin ? To further elaborate, I also noticed the sockets green, yellow, brown and white wires were connected to a harness and there was another white wire attached to the chassis. Oddly there was another yellow wire from the socket which also didnt connect to anything else. Thinking that even though it was 7 pin socket it had been wired like a 4 pin which seemed to be the case since the turn signals, hazard and running lights all functioned. I thought even 4 pin sockets also needed a wire going directly to the battery in order to function?

asked by: Yohan B

Expert Reply:

The Wiring Kit # 5506 will provide you with the wiring needed to get power to your charge line and wiring for a trailer brake controller on your 2018 Toyota Highlander. It sounds like someone simply added a 7-Way # HM47210 and only wired in the 4-way way functions along with the ground wire so the lights would work on their trailer.

I recommend using the Redarc Tow-Pro Liberty Brake Controller # RED52VR which will include a universal wiring harness. The small control knob will fit inside the Mounting Panel # 331-TPSI-002 allowing for a clean factory appearance.

expert reply by: Bud M