Installing a Brake Controller on a Freightliner M2-106 with Air Brakes

Question:

I have a 206 frieghtliner m2-106 with air brakes and I need to have electrical brake controller installed and I am have a hard time finding the brake wire, the wires for brakes also control the tun signals, so my question is where would I find a hot brake that would only become hot when I hit the breaks

asked by: Stev R

Expert Reply:

Trucks with air brakes might not have wire at the brake switch for a brake controller but I do recommend checking that first. The brake switch should be located above the brake pedal with wires going in and out of it.

Use a circuit tester such as # PTW2993 to test the wires (the truck may have to be on, but not running). You need a wire that only shows power when the brake pedal is pressed and not when the headlights or turn signals are on.

If you cannot locate a wire at the brake switch, then check the owner's manual for the location of a stop light or CHMSL fuse that you can tap into using a fuse tap. As long as the circuit is a dedicated brake light only circuit and nothing else is fused with it you can use that circuit.

A coworker determined that there should be a 30 amp stop light fuse in the Trailer Fuse Box and a 20 amp stop light fuse in the Taillight Fuse Box that you could run a fuse tap to so check those locations as well.

expert reply by: Michael H