Troubleshooting Electric Brake Controller Not Recognizing Trailer Connection

Question:

I just installed a Reese 8508700, I do not get a Green Light when connected to my trailer. Also no red light when I step on the brake even with gain at full. I do get a red light when I push the knob controller, this has no effect on the used trailer I just purchased. The camper has two axles, I am thinking wiring problem with trailer. Do you have any another suggestions?

asked by: David L

Expert Reply:

With no green light on your Brake Controller 8508700 when you are connected to your trailer there is something wrong in the wiring either on the trailer or on your tow vehicle. You can use a Test Light # PTW2993 to check the wiring at your 7-way connector both on the rear of your tow vehicle and just past the trailer connector to determine where your issue is.

On your 7-way the blade terminal located at the 5 o'clock position is the one that goes to the trailer brakes. If the test light connects to it and a ground source on your vehicle you should get your green light. From there you can continue back on the trailer side and follow until you find the point where the green light doesn't illuminate. That will identify where you have a bad connection.

expert reply by: Bud M