How To Install the Adapter 4-Pole to 7-Pole and 4-Pole 37185 On a 2003 Toyota Highlander

Question:

hello there....the wiring instructions that came with my Hopkins 4 Pole to 7-Pole Trailer Adapter Vehicle End Plug Item # HM37185 are so limited theyre worthless. I have a 2003 Toyota Highlander with a factory tow-prep package. Ive mounted the Hopkins End Plug to the hitch and connected the male end of the Highlanders 4-flat plug into the female 4-flat socket from the Hopkins End Plug. Ive connected the trailers 7-blade socket into the Hopkins End Plug. The trailer now has running lights, brake lights, and turn signals. My trailer has electric brakes and it has coach batteries that need charging while the trailer is being towed. It has an on-board battery charger to charge the coach batteries from the tow vehicle. Therefore, I need to finish wiring the black, blue and purple wires from Hopkins End Plug. Ive grounded the white wire to the tow vehicles frame. Instead of adding a wired brake controller, Im going to use the Curt Echo wireless brake controller to operate the trailers electric brakes. I also want to operate the back-up lights on the trailer. What do I connect the the black, blue and purple wires to, where exactly are these connections made, and what kind of connecter should I use for each. Thank you very much ! Thank you.

asked by: Richard

Expert Reply:

I am sorry to hear about the trouble you are having with the Adapter 4-Pole to 7-Pole and 4-Pole part # 37185. This is a universal harness so the instructions won't be specific to any one particular vehicle. The black wire is for 12 volt power to the trailer or in this case, the Curt Echo Mobile Trailer Brake Controller part # C51180 which will also provide a small maintenance charge to your trailer battery. This wire will need to be run to the positive side of the battery terminal with part # 10-1-1 and part # PK54540. The blue wire will just be taped off and secured under the vehicle as you will not need this for the Curt Echo Mobile Trailer Brake Controller. The purple reverse wire will then need to be spliced into the reverse light circuit with part # SWC502905-1. The best place to find the reverse wire is behind the tail lights but you will need to test with a circuit tester to make sure you have the correct one.

expert reply by: Conner L