Troubleshooting Brakes Not Working With Brake Controller on Jeep Grand Cherokee

Updated 12/17/2018 | Published 12/15/2018

Products Featured in This Question

Pollak Replacement 7-Pole, RV-Style Trailer Connector Socket - Vehicle End

(745)

$15.62

Cordless Circuit Tester

(15)

$20.00

Question:

Recently bought a used Jeep GC with factory tow package. I easily removed the Tekonsha brake controller from our old Expedition, but did not want to drill into the Jeep, so brought controller to the local mechanic for installation. Plugged in the trailer and all connections work except the brake controller. I was suspicious when I picked up the vehicle as when I step on the brake without the trailer hooked up, the green light on the controller briefly lights up, then goes off. Never happened with the Expy. . . . . Any ideas?

asked by: Pca

Expert Reply:

There is some troubleshooting I can help guide you with, and though you never mentioned what Tekonsha brake controller you have, I am going to assume it is the Voyager # 39510 because you mentioned the green light going on without your trailer connected.

If this is happening that means the Voyager is picking up a load on the blue brake output wire. This could be a number of issues but I would start by taking a look at the connector on your Grand Cherokee. If there is corrosion on it, which is green or white, that may be interfering and you would need to clean it out or replace the 7-way on your Jeep.

Should there not be any corrosion the next step is to sever the blue wire a couple inches from the back of your controller, then use a circuit tester such as # PTW2979 to test the end of the blue wire coming out of the controller. It should only have power when you apply the manual override; if it shows power at idle then there is an issue with the controller and it will need to be replaced.

If the controller tests fine then you will want to test the brake output pin on the 7-way socket; it should only show power with the manual override. If it shows power any other time then there is a short somewhere between the connector and the brake controller you will need to find.

I have also attached some help articles on testing and troubleshooting brake controllers which I highly recommend checking out.

expert reply by: Kyle S