'94 K2500 gasser. Truck has a brake controller.

A buddy of mine has turn signals, tail lights, back-up lights, and the third brake light on the cab works. However, he has no normal brake lights. He also says he has no power at the harness in the rear of the truck for the brake lights when he pushes on the brake pedal.

I've suggested to find the brake switch and follow the leads thinking there might be a wire break somewhere.

Can anyone else offer help on this? Can I give more details I may have left out?

Thanks,
SnowDrift

Most likely a bad turn signal/multifunction switch in the column.
Power for the side brake lights runs through the switch, so turn signals can blink with brake lights on. The third light runs straight from the brake pedal switch to the lamp, you may have noticed some cars that the 3rd light comes on a fraction of a second before the others, that's due to the power taking longer to go through the switch.

Chek All of the fuses,mine did the same thing.

Easy first, check the fuses under the dash. Then check the ground at the dr. rear of frame near the bumper brackets.