Troubleshooting 4-Pole Wiring Harness on 2003 Lexus RX300

Updated 06/21/2017 | Published 06/20/2017

Products Featured in This Question

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

(120)

$18.94

Curt Powered Tail Light Converter w/ 4-Way Flat Trailer Connector and Install Kit

(141)

$167.51

Question:

I installed this product around a year ago and have recently noticed none of my lights on trailer are working. I used test light at end on plug- no power and checked fuse.. I have read online some people had to hard wireinch to the inside connection plug by spare tire.

asked by: Sherman

Expert Reply:

Tekonsha 4-pole wiring kit # 118245 is the correct OEM replacement harness for the 2003 Lexus RX300 with factory tow package. If you checked the fuse and tested the pins on the 4-pole plug and have no power on any of the 3 circuits I suggest you unplug the harness and test the OEM connector on the vehicle where this part plugs in.

If you have signals there, upstream of the 4-pole harness, then the harness may be bad. If you do not have signals there then there may be an issue within the vehicle wiring. Check for any bent or broken electrical contacts within the connectors.

You also have the option of installing a 4-pole that is independent of any tow package wiring. Such a harness kit # C59496 will hardwire into your taillight wiring and provide the same lighting signals. A help article and video are linked to show how to install this 4-pole kit.

expert reply by: Adam R