Reliance Trailer Brake Controller Shows No Trailer Attached with a Trailer Attached

Question:

have a Reliance controller with no plug. 1998 k2500 chey truck. I have the code from the controller telling me that the trailer is not connected even though it is and the brakes are working. the controller is not adjusting the brakes. I have the black wire going to the battery and the white is neg/ground on the battery the blue is connected directly to the blue axuilary brake wire in the rear of the truck. the red wire is connected to the stop light wire in the rear of the truck and then run straight to the the electric brakes. the neg or ground for the brakes is tied to the ground for the lights. I do not have a trailer plug so I had to run a seperate wire the stoplight wire from the truck. what am I doing wrong ?

asked by: Cody

Expert Reply:

First, I would check the pin that the blue wire is attached to. If you are looking at the back of the 7-Way on the truck, the brake wire should be connected to the pin in the 7:00 position. Make sure that the trailer side connector brake pin is in the corresponding location on its connector.

The 7-Way on the truck will also need to be grounded to the truck frame. If it is not, the circuits going to it will not be completed. You can test the output of the controller by using a circuit tester like # 3808 and testing the brake pin on the ruck while someone fully engages the manual override on the brake controller.

If no power comes through then test the blue wire directly behind the brake controller. If there is still no power then there is a problem with the internal circuitry of the brake controller and it will need to be replaced. If it shows power at the back of the controller but not the 7-Way then there is a wiring issue somewhere between the two you will need to track down.

make sure that the trailer and vehicle connectors are clean and corrosion free and that the main ground from the trailer connector is attached to the trailer frame. I would also move the brake magnet ground wires to the trailer frame.

expert reply by: Michael H