Is Pulsing Brake Controller Circuit Normal Operation

Question:

While putting a voltage tester to the truck side brake plug pin I am getting a dim slow pulsating light. I have already replaced the factory integrated brake controller. Could the trailer brake relay be causing the problem? So far the wires I can see look good. I did a minimal inspection of the relay and it looks to be in good condition

asked by: Sandy D

Expert Reply:

Thanks for reaching out!

What you're seeing actually sounds normal. Brake controllers, like the Primus IQ # TK90160 and others, will send a small pulse on the brake controller circuit to check and see if a trailer is connected or not. This is standard operation and won't damage any circuits or anything.

If you start getting weird messages on your controller or 2011 Chevy Silverado 2500 then that's when we need to be worried about something being messed up.

expert reply by: Jon G