Constant Power to Trailer Brakes and Red Light Always On the Brake Controller
Question:
when i connect my camper trailer to vehicle the red light is constantly on bright and no brakes on trailer when activated. upon diagnosing i have found there is a constant power feed to the trailer and if i earth the black wire directly to chassis. the brakes lock on without pedal aplication.
asked by: Dion F
Expert Reply:
It sounds like there is a short to the blue wire (brake output) on the brake controller. This can be caused by corrosion in or behind the vehicle and trailer side connectors. Power from the 12 volt circuit at the vehicle side connector could be jumping to the brake output circuit. This would make the brake controller think there is power being applied and when the trailer is connected it can send full power back to the brakes.
To eliminate the brake controller as the problem, cut the blue wire from behind the brake controller and test it with a circuit tester like # 3808. It should show power when you apply the manual override but if it shows power without the override engaged then there is a short inside the controller and it will need to be replaced.
You can also check the red wire with the circuit tester. It should only show power when you step on the brake pedal.
If you eliminate the brake controller as the problem, you can also try resetting the controller. It has to be mounted in such a way so as to work properly. Follow these steps to set up the brake controller:
A. Connect the trailer to the tow vehicle for this adjustment. If a load leveling hitch system is used, it should be connected and operational. Locate the tow vehicle and trailer on a flat level surface. Make sure the tow vehicle stop lamps are operating correctly and disconnect the tow vehicle/trailer electrical connection.
B. Adjust the gain wheel to its maximum setting.
C. Depress the brake pedal far enough to turn on the vehicle stop-lamps. Hold this position.
D. Pull the pendulum leveling arm toward the red indicator light. The red indicator light should illuminate bright red.
E. Push the pendulum leveling arm away from the indicator light until the light just reaches minimum brilliance. The leveling arm should be approximately straight down. Repeat steps D and E several times to make sure the indicator light has just reached minimum brilliance.
F. Release the brake pedal. The pendulum is now initially adjusted. A readjustment may be necessary if the loading of either the tow vehicle or trailer causes a considerable change in the tow vehicle front to rear position. Also a further readjustment may be desired during road test and performance adjustments.
On the brake controller, the black wire is the 12 volt power wire and should have 12 volts of power. The white wire is the ground. Take a look at the wiring FAQ article I have linked for you. If your truck and trailer are pinned out differently and do not match, this could be causing some problems as well.
There could also potentially be an issue with the trailer brake magnets. To test the magnets you can follow the FAQ article I have linked.
Austin
3/16/2013
Just had activator 2 brake controller installed on 2001 chevy 2500. When hooked up to my trailer the display shows nothing. I was wondering if that is how it should be or if there should be a decimal constantly showing when hooked to trailer? Thanks.