Trailer brake issues

I have an 07 Tacoma double cab TRD Sport with the factory tow package installed, 7 pin connector.

The issue I'm having is knowing what the voltage should be on the blue brake wire when in park with brake pedal pressed. I'm getting millivolts and don't know if it gradually feeds voltage while braking in tow or I've got issues. This is my first trailer with brakes. Everything else on that connector gives me 12+ volts where it should be.

Side note, I've went through all the relays and fuses, plus I have put in a new factory controller in the driver side kick pannel. I've also back traced all of the wires to look for cuts.

 

It depends how your controller works, some won't output anything unless they sense a load on the circuit.
I always test them with a test light.