What does blue wire mean on brake controller?
Since your brake controller shows no red light this indicates a short to the brake line (blue wire). If you are using wiring harness, # 3040-P, make sure that extra white ground wire is attached to a clean bare metal surface.
Why is my blue wire showing no voltage?
If it is hardwired to the truck, the ground needs to be connected to the negative battery terminal. Sever the blue wire a few inches back from the controller and use your circuit tester to test the wire. If it shows voltage without applying the manual override, then this indicates a problem inside the controller and it will need to be replaced.
What does blue wire on tow truck controller mean?
Also, the blue wire is showing positive voltage without the brake pedal being depressed. When I test that wire for voltage, the light on the controller lights up green, indicating that the trailer is hooked up even though it isnt. Should that blue wire have constant voltage the #2 pin also has constant voltage at the tow vehicles 7-pin connector?
Where is the blue wire on a trailer?
Check that the blue wire is securely attached at the rear of the connector. You can trace the blue wire back toward the front of the vehicle, looking for breaks in the wire. If you cannot trace the wire the whole way back to inspect it, you might need to replace the wire entirely.
How do I test the blue wire on my brake controller?
If your brake controller is receiving power, set the power gain to maximum voltage and sever the blue wire about 6 inches back from the brake controller. Using a circuit tester, like part # 40376, test the blue wire for power when you activate the manual override of the brake controller.
Why is there no power on the blue brake output wire?
If there is no power on the blue wire when the manual override is activated, the brake controller is probably bad and would need to be replaced. If you have a proportional brake controller and are testing for power when the brake pedal is pressed, there will be no power on the blue wire.
If it is hardwired to the truck, the ground needs to be connected to the negative battery terminal. Sever the blue wire a few inches back from the controller and use your circuit tester to test the wire. If it shows voltage without applying the manual override, then this indicates a problem inside the controller and it will need to be replaced.
Also, the blue wire is showing positive voltage without the brake pedal being depressed. When I test that wire for voltage, the light on the controller lights up green, indicating that the trailer is hooked up even though it isnt. Should that blue wire have constant voltage the #2 pin also has constant voltage at the tow vehicles 7-pin connector?