Troubleshooting New Installation of Hidden Hitch Pilot # 80550 Trailer Brake Controller

Question:

Followed directions and hooked up pilot today. With no trailer attached red light comes on controller when I brake like it should. When I hook to my trailer light on controller does not work neither does the brakes. Running/brake/turn signal lights on trailer work fine. Trailer 20 yrs old and not been used in last 5 plus yrs. Ran new brake wires to brakes and grounded to frame with no result so I ran ground into my 7 pin and grounded there same result nothing. Replaced my 7 pin with no result. I just wondering what the heck to do now.

asked by: Dustin O

Expert Reply:

Thank you for detailing the troubleshooting steps you have taken to find the problem with your installation of the Hidden Hitch Pilot # 80550 Time-Delayed Brake Controller.

First, apply a tester like # PTW2993 to the red (input) wire to the controller; if you detect a signal on this red wire then you know the vehicle's brake signal is making it into the controller. If there is no signal on the red input wire, then check your installation to be sure you have the red wire attached to the cold side of the brake light switch (the side with a voltage only when the pedal is pressed).

Next verify that the controller is sending out a brake signal. Apply the circuit tester on the blue output wire. If you detect a brake signal on this wire when you apply the manual override lever, then you know the unit is sending out the brake signal. You can also test this blue wire by applying the brake pedal and waiting for the controller to respond. If there is no output signal at the controller, then the unit is bad and needs to be replaced. If this is the case, I suggest a proportional controller like the Tekonsha P2, part # 90885.

Once you know the controller is working you can use the tester as you move downstream in the vehicle wiring. Check for the brake signal at the blue wire leading into your 7-way. If it is there, then test for signal on the socket's contact pin. If you do find the signal on the 7-way, then the issue is likely to be a loose or intermittent connection on the vehicle side or there is an issue with the trailer's plug.

Check all contact surfaces for signs of even slight greenish or whitish discoloration, either of which indicates corrosion that could interfere with signal transmission. Since the trailer has been sitting for a few years, it is not surprising that there may be an issue with its wiring. You can connect the trailer to the Silverado and apply the tester to the brake circuit wire to find the point where the signal is lost.

Since the trailer has been sitting, there could easily be an issue with the brake magnets. I have linked an article describing how to test the magnets.

The linked articles on brake controller installation and troubleshooting will offer you additional guidance.