Curt Discovery Brake Controller Is Only Showing A Dot When Engaging Manual Override

Question:

curt discovery brake controller. The brake controller is showing a . when you hit it. Nothing else is being displayed and we are unsure if this is a wiring issue or what. The vehicle is a 2016 nissan pathfinder.

asked by: Samantha

Expert Reply:

The Curt Discovery Trailer Brake Controller, # C84VV, should show only the decimal point dot when the controller is activated and a trailer is not connected. If it shows the dot all the time, the red wire is connected to the wrong side of the stop light switch or the wrong switch completely like the cruise control.

If you have only the decimal point when the trailer is connected, the usual cause is that the brake controller does not sense the trailer brakes. This could be due to corrosion on the the trailer connector or a broken or damaged wire somewhere between the brake controller and trailer brakes.

To test for this, I recommend using a circuit tester with an incandescent bulb, like part # PTW2993, to test the 7-way connector at the back of your vehicle. This will be the 5 o'clock pin. A tester with an incandescent light will simulate the draw from a trailer brake magnet and trick the brake controller into thinking that a trailer is connected. If you get a power read out on the brake controller display when using the circuit tester, then we know the issue is on the trailer.

If you still get the decimal point, then there is a problem on the brake output wire, or blue wire from the brake controller, between the brake controller and trailer connector. If you cannot find the problem after examining the vehicle wiring, you can bypass that wire by running a new 10 gauge wire from the blue wire at the brake controller to the 5 o'clock pin at the trailer connector.

With a trailer connected you should have reading on the display and be able to adjust the dial on top and the slider on the side to adjust for you needs. I've attached the instructions to help and I've also attached a video for you that shows exactly how the brake controller should act with a trailer connected and without a trailer connected. It shows this in the first 2 minutes.

expert reply by: Jason S