Curt 56042 4-Pole Trailer Connector Installed on 2017 Toyota Highlander and it Doesn't Work

Published 07/01/2021

Products Featured in This Question

Curt T-Connector Vehicle Wiring Harness for Factory Tow Package - 4-Pole Flat Trailer Connector

(168)

$15.94

Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector

(1089)

$42.08

Question:

I installed a 56042 Curt T-Connector Vehicle Wiring Harness for Factory Tow Package - 4-Pole Flat Trailer Connector On my 2017 Toyota Highlander and installed a 30A fuse in the proper spot. Trailer lights still not working. What else might I check?

asked by: Jason

Helpful Expert Reply:

The T-connector trailer wiring harness for the 2017 Toyota Highlander consists of two different parts, the connector itself which is part # 56042 you purchased as well as a converter box that completes the tow package.

The # 56042 is actually intended to replace a damaged trailer connector on vehicles already equipped with the tow package wiring. Therefore, if the # 56042 is installed on a vehicle that does not have the tow package, the trailer wiring would be incomplete and wouldn't work.

You can confirm whether your Highlander was equipped with the factory trailer wiring tow package by checking under the threshold in the cargo area. Look about 14 inches toward the driver's side, and if there isn't a converter installed in the white 10-pin connector (see provided photo) then the vehicle isn't equipped with the tow package and the converter would need to be installed.

If that's the case, you'll need the # C56217 which includes both the 4-pole connector that plugs into the 4 pin shown in the same photo but also the converter unit. Unfortunately, the converter isn't sold as a separate item minus the 4-pole but this way you'll have an extra 4-pole harness in case the existing one gets damaged. Once the converter is installed, the trailer connector will work fine and you'll be good to go.

I've linked to an installation video for the # C56217 converter/harness.