I can drive home and park my truck tonight, but I have to get this figured out by tomorrow evening.

At some point my brake lights quit working, noticed this morning. I've looked at all the fuses I can think of, none blown. The running lights work, the signals and flashers work (both bulbs didn't burn out simultaneously). My brake controller senses when the brake pedal is pressed (a little light in the corner), and recognizes that a trailer is not connected at start up. It doesn't seem like that is the problem. I went ahead and replaced the brake switch, apparently that wasn't the problem.

Does anyone have any ideas. Are their relays that affect brake lights? The descriptions on the fuse box under hood are rather vague. Anybody with a wiring diagram that I could start tracing wires from the brake pedal switch.

Help.

Thanks.

 

Update. The brake controller now does not recognize when the brake pedal is being depressed (indicator light in the corner). I replaced the switch again just to make sure. Same results. I hooked the truck up to a trailer. All except brake lights work. When the controller is manually pressed to set the brake strength, that works fine, but no lights.

Does anyone have a service manual with a wiring diagram that could tell me what the hot lead into the brake pedal switch is.

I'm completely stuck. Any help would be appreciated. I did remove brake controller to see if that was a cause. Same results.

 

The lead into the brake pedal switch is a ground.
Have you tried unplugging the brake controller?
It might be the problem.

 

The only place the power goes from the brake light switch is through the multifunction (signal light) switch before it heads rearward. Cycle the hazard switch a few times, its contacts might be dirty, then see if it made a difference. You can see if the signal is making it from the brake light switch, but you would need a diagram. If your signal lights are working at the back, this would be a reasonable part to assume is bad. Could also be a broken wire or loose terminal leading to the multifunction switch, as tilt steering use will fatigue these over the years.