Troubleshooting Electronic Brake Controller Stating No Trailer Connected

Updated 10/30/2017 | Published 10/28/2017

Products Featured in This Question

Hook Probe Circuit Tester

(66)

$14.40

10 Gauge Wire - Blue Primary - Per Foot

(108)

$1.61

Dielectric Grease for Electrical Connectors, 2 oz.

(1494)

$11.41

Question:

Why isnt the truck recognizing that the trailer is connected? The trailer has electric brakes and the truck has a towing package with a brake controller.

asked by: Jim M

Expert Reply:

When a brake controller isn't recognizing a trailer connected, the first thing to do is check the trailer connections for corrosion or debris. Clean the terminal connections to make sure they are getting a clean metal to metal connection. Most of the time, it is just a bad connection at this point that gives your brake controller this error in trailer connection. I recommend using dielectric grease # 11755 to help keep moisture and debris out of the connection while assisting in the electrical connection.

If the pins on your vehicle are clean and the receiving side of your trailer connector are clean, then check the brake function using a circuit tester like # PTW2993. Test the pin at the 5 o'clock position on your vehicle side connector when the trailer is not connected using the brake pedal and the manual override connection. If you don't receive a reading on the circuit tester then I recommend you test the wire behind your brake controller (brake output is normally blue) for function. Test about 6 inches behind using the same circuit tester. If you don't have function there, your brake controller is not functioning properly. If you have function there, but not at the trailer connection, there is a short in that brake output wire and you will need to run a different wire using # 10-1-1 sold by the foot.

expert reply by: Jason S