2006 Ford Expedition I had thes control and bought the new harness to adapt to the control. the color code is the same. The control will not show voltages or the letter C when plugged to rv. All lights work and brake lights work. there is about 5V on the blue wire going to the rv from hitch plug. Thats all I can get whether I roll the control wheel either way.
asked by: Jim A
I would start by doing a standard troubleshoot on the controller. Use a circuit tester on the black wire exiting the rear of the controller to ensure the controller is receiving power. Test the red wire and make sure there is voltage when the brake pedal is pressed. Test the blue output wire as the manual override is actuated to check output.
If all checks out to this point, examine the trailer connector. Make sure it is not damaged or corroded. If you can see any green corrosion on the pins of the connector, there is a chance that the corrosion has spread to the interior of the connector, and is preventing the signal from the controller from passing through. Also check the connector on the trailer itself, checking for damage or corrosion.
Please let me know what you find, if the controller or either the connector on the vehicle or the trailer is the culprit, we can continue troubleshooting.