Troubleshooting Brake Controller with 1.5 on Display All of the Time

Updated 06/16/2020 | Published 06/14/2020

Question:

Hello, i have a predator dx2 brake controller and with no trailer hooked up it shows about 1.5 constantly on the display with the lights on. And with a trailer hooked up it shows it also. What would be cause? Is it keeping the trailer brakes applied at all times? Thanks

asked by: Trevor D

Expert Reply:

Sometimes brake controllers need to be reset as they get a weird internal bug. Try unplugging yours for a minute or so and replugging in and see if that helps. Here's how to test the controller though:

Testing the brake controller is fairly easy. Sever the blue brake output wire near the brake controller leaving enough room to reconnect it and then apply the manual slide. Using a circuit tester like the Tester, part # PTW2993, you should get output to the controller side of the wire you severed. If the manual slide activates the trailer brake output wire properly, try the brake pedal. If the brake pedal activates the brake output properly also then the problem is farther back either in the vehicle wiring or on the trailer.

If either the brake pedal or the manual slide are not functioning properly you will need to test the wires going into the brake controller. Make sure you have power entering the brake controller on the black wire. On the red wire you will only want power when the brake pedal is pressed.

If there is power on the red wire before the brake pedal is pressed you have connected the red wire from the brake controller to the wrong circuit. You would then need to find the brake switch wire that has power ONLY when the brake pedal is activated.

I am including a link to a video that will show you how to test the wiring on a brake controller. If yours ends up being faulty the iCommand part # 5535 would be a great replacement solution.

expert reply by: Jameson C