I have a '93 F-350 with a brake controller installed by previous owner. The controller works fine and the trailer brakes work too, but only when I slide the lever over. When I hit the brake pedal nothing happens....the light on the controller stays green and no brakes are applied to the trailer. Can someone explain what this might be? Thanks

 

Sounds like you are not getting a signal from your brake light switch. Or the controller is bad.

 

There should be a dial on it to set the power level going to the trailer brakes. My first thaught is that it is turned way down.

 

What kind of controller is it? Is it the old hydraulic style like this? Theres a T on the brake master cylinder, and a steel brake line coming through the firewall, heading in this controller.




That little level should move to one side as you step on the brake. (mine moves to the left).

They are adjustable, mine starts moving after the brake pedal goes down at least 1 inch.


These are the dinosaurs of brake controllers though.

 

That is old. .... Bad thing is I have put several of them on...

 

I do not know the brand off of the top of my head but I do know its not the old hydraulic style. The brake controller is adjusted properly and my trailer brakes work well when the lever is slid over. However, my trailer brakes do not come on when the brake pedal is pushed, nor can anyone hear the electro-magnets at the axle when the pedal is applied. Everything works as it should when sliding the lever over.
My controller plugs right up to the factory harness, not manually wired in like some of the older ones. Could this mean that my controller is bad like Catfish 101 said or is there just a wire missing from the break switch.
-Thanks

 

Could be either. If you can trace the wires from the factory harness that might get you some insight on how its connected. I'll second the adjustment thing, perhaps its not set right and thats why the pedal does nothing, but the manual slide will work.

Can you post a picture of it?

 

Its adjusted properly. I have 4 different trailers with different weights that I pull on a regular basis.

 

There is a 30 amp fuse that feeds the control box, from panel outside under the hood, and the brake light switch signal comes from a splice that goes to the lights on the truck and the trailer. The feed line is a red wire and the brake light switch is a light green to at the controller. Going to have to check voltage there. when you hit the pedal. Sounds like your 30 circuit is ok though or you wouldn't have anything at the box.