Testing Brake Controller that Only Works with Manual Override Lever
Published 01/29/2015 >
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Question:
When I apply pressure to my brake my trailer brakes do not work but when I manually squeeze the trailer brake controller they work. It is a factory trailer brake controller. What could be causing this?
asked by: Trent
Expert Reply:
First thing to do is look for and clean any corrosion on either your vehicle's 7-way wiring and the trailers connector.
Testing the brake controller is fairly easy. You will need to be able to access the brake controller wiring which should be behind the dash area near the controller's location. Sever the blue brake output wire near the brake controller leaving enough room to reconnect it and then apply the manual slide. Using a circuit tester like part # PTW2993, you should get output to the controller side of the wire you severed. If the manual slide activates the trailer brake output wire properly, try the brake pedal. If the brake pedal activates the brake output properly also then the problem is farther back either in the vehicle wiring or on the trailer.
If either the brake pedal or the manual slide are not functioning properly you will need to test the wires going into the brake controller. Make sure you have power entering the brake controller on the black wire. On the red wire you will only want power when the brake pedal is pressed.
If there is power on the red wire before the brake pedal is pressed you have connected the red wire from the brake controller to the wrong circuit. You would then need to find the brake switch wire that has power ONLY when the brake pedal is activated.
If these connections check out and the brake controller is properly grounded then there is possibly a problem inside the brake controller.
I am including a link to a video that will show you how to test the wiring on a brake controller.
Product Page this Question was Asked From
Ford Replacement OEM Tow Package Wiring Harness, 7-Way (Super Duty)
- Custom Fit Vehicle Wiring
- Trailer Hitch Wiring
- Vehicle End Connector
- No Converter
- Factory Tow Package
- 7 Blade
- Plug and Lead
- Plug-In
- Visible
- Tow Ready
more information >
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