Where to Find Stoplight Circuit in a 1990 Ford Truck for Brake Controller Install

Question:

I bought a truck with a break controller installed but the previous owner said it did not work properly and caused problems with the antilock break system. I have looked online for a wiring diagram to correct the problem but have come up empty

asked by: Josh D

Expert Reply:

If a brake controller is causing an issue with the anti-lock brake system the issue is the way it is wired to the truck. The red wire of the controller is the issue. It needs to be ran to a circuit that only sees voltage when the brakes are applied. Sounds like this wire is ran to the wrong circuit.

For Ford trucks of your era there is a unique place to find this circuit. I attached a diagram that has where to find this circuit.

expert reply by: Jameson C