Troubleshooting 4-Pole Connector Not Testing for Turn Signals on 2002 Toyota Sequoia

Question:

I have a 4 prong wiring harness already installed. Battery tester shows power and all 3 lines steady no blinking for turn signals. All lights work on trailer/pop up I want to tow as I tested on my Dads pickup. When I plug in trailer to Sequoia, no lights come on. Where do I start trouble shooting to find the problem?

asked by: Ray C

Expert Reply:

If your 2002 Toyota Sequoia has a factory trailer tow package wiring that the 4-Pole connector is plugged in to, you can test the factory wiring to ensure it is functioning properly.

Unplugging the 4-Pole connector will provide access to the pins for the factory wiring. You will want to use a circuit tester, like # PTW2993, to test the pins on the factory wiring. They should test for taillights, right stop and turn, and left stop and turn. I have attached a video on testing with the # PTW2993 for you.

If the factory wiring connector tests correctly for all of the functions, it is likely that the trailer connector will need replaced. If the wires on the 4-Pole connector are pinched or damaged, this could be causing a short in the connector. If you need a new 4-Pole connector, I recommend the Curt # C55246 for your 2002 Sequoia.

If the pins on the factory wiring do not test correctly for their functions, and you want to continue using the factory wiring, you will want to take your Sequoia to your local Toyota dealer for them to inspect the factory wiring on your vehicle. Otherwise, you could use a trailer wiring harness that will hardwire install for your vehicle, like the Upgraded Heavy-Duty Modulite Circuit Protected Vehicle Wiring Harness with Installation Kit # C59496.