Troubleshooting Brake Controller Install Where Turn Signal Stays On All the Time When Connected

Question:

I am wiring a brake control in. I have the exact setup in this writeup: https://www.etrailer.com/faq-Ford-Full-Size-Van-Brake-Controller.aspx I have the fully functioning 7 pin at the back now, installed as per the above link. Everything works great on the 7 pin. Now I installed a Reese Brake-Evn controller with the correct plug n play harness under the dash. As soon as I plug in the brake controller to the harness, the right turn signal lights up solid on the dashand outside lights. It turns on with, or without the key in the on position. The turn signal lever does not over ride it. Nothing lights up on the controller. I already tried a second controller to see if the controller was defective. What is wrong and what do I need to do to fix it??? I need to tow a trailer ASAP! Thanks.

asked by: Carsten

Expert Reply:

The brake controller install wiring of your van somehow is not wired correctly. Best option we have to get you on the road quickly is going to be to bypass all of the factory wiring and then hardwire the controller in. Most likely you can leave the power and ground wires of the controller connected to the factory wiring (black and white wires) but first try severing the red wire of the controller leaving enough room to reconnect it to see if the turn signal issue goes away. If so, then you know the problem is on the stoplight circuit of your vehicle. You can then use a circuit tester like part # PTW2993 to test the wiring that leads to your brake pedal till you find a circuit that only has 12 volts when the brakes are applied to connect it to.

If the problem stays after cutting the red wire reconnect it and now cut the blue wire. If the problem goes away now you'll have to run a length of 10 gauge wire like part # 10-1-1 (sold by foot) to the 5:00 pin of your 7-way and you'll have bypassed the problem.

expert reply by: Jameson C