i have a 2001 gmc 2500 4x4. a month or so back my brake lights stuck in the on position. originally thought it was the brake pedal switch and replaced it with no success. i began troubleshooting beginning starting with the bulbs and wiring. when i unplugged the main feed going into the junction box in the rear of the vehicle i noticed some dirt in the connectors. cleaned them all out plugged them back in and the brake lights worked great for about 20 minutes of testing in the garage then back to square one i replaced the junction box and nothing. i have retraced all the wires and they are in good shape. even the circuits are good. does anyone have any other ideas or suggestions to fix this problem? anything at all would be helpful.