Tekonsha Primus IQ Brake Controller Screen Goes Blank when Stepping on Brake Pedal

Question:

Trailer connected lights and 4 way flashers work. Push break pedal or manual override and screen goes blank. and stays blank not allowing me to set output value. Please advise

asked by: Morris B

Expert Reply:

When the Primus brake controller # TK90160 goes blank when you step on the brake pedal that indicates that the brake controller has lost power or the ground has been interrupted.

Power could be lost if the draw of the brake magnets is overdrawing the circuit, especially if it is a hardwire installation that uses resetting circuit breakers. I recommend a 30 amp circuit breaker # PK54530 which would be more than enough for up to 6 brake assemblies.

The loss of ground is harder to figure out. Basically at idle the controller doesn't have much power running through it so a weak ground goes unnoticed. Once there is more power draw though it is too much for the weak ground to complete the circuit. The best place to ground a brake controller is to the negative battery terminal.

What vehicle is the controller in? And is it hardwired in or plugged in with a vehicle specific harness?

I have included some links to our help articles on testing and troubleshooting brake controllers for you as well.

expert reply by: Michael H