Recommended Wiring Harness for 2020 Toyota Highlander

Updated 06/01/2025 | Published 06/04/2021

Question:

U-Haul tried to install a Curt 56452 Custom 4-Way Flat Trailer Wiring Harness on my 2020 Toyota Highlander XLE and the connectors did not match up. On the box cover, it clearly indicated that the Curt 56452 should work on my 2020 Toyota Highlander. Can you explain why the 56452 did not work? Are you confident that if I order your part # C76CR that the connectors will match up?

asked by: Barclay W

Expert Reply:

The Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector # C76CR is confirmed to fit the 2020 Toyota Highlander without the factory tow package. If you have the factory tow package you need the # TK74FR T-One Vehicle Wiring Harness for Factory Tow Package - 4-Pole Flat Trailer Connector.

The # C76CR plugs in using the t-connector behind the rear driver's and passenger's side tail lights. The # TK74FR connector plugs into the factory tow package wiring harness, located behind the rear bumper on the driver's side. If you do not have the factory tow package it is possible to still have the plug, it will just be inactive.

Without being there during the attempted installation or seeing the connection it is impossible to determine the reason why the connectors did not match up. It is possible that there was a manufacturing error, or the installation technician made a mistake and attempted to connect the plugs from this kit into the tow package wiring harness. The only other possibility is that they had a Curt wiring harness for a 2021 or 2019 or something similar. This harness only fits on the 2020 Highlander.

I have attached the installation instructions for both that you may reference.

expert reply by: Robin H

Mike

5/31/2025

Hi Robin, I installed the CURT 56452 on my 2021 Highlander XLE and now I get a Brake Power Loss Error. Can you please advise why it may be doing this? Thanks, Mike

Robin H.

6/1/2025

@Mike like an error on the dash of the vehicle? The Curt wiring harness plugs in-line with the wiring at the tail lights and has its own power from the battery so it won't impact anything like that on the vehicle. It sounds like something else might have happened during the installation, unrelated to the wiring harness itself. I would take it to a local dealer and have them check it out.