I have a 97 Tahoe and the brake lights were not working and the problem was in the emergency flasher switch. I just jiggled it and the brake lights worked so am thinking you might have the same problem. It could also be the brake pedal switch located right on the pedal arm.
Determine which circuit is involved and then troubleshoot that circuit You should take your truck to Autozone and have them check the charge on your alternator, they do this for free.
Panel lights and parking/tail lights should be on 1 circuit Brake lights should be on a separate circuit If you are sure fuses are good- Check bulbs Check headlight switch Check stoplight switch
Check the fuses. Parking lights/tailights/dash lights should be a common circuit Check the fuses. Parking lights/tailights/dash lights should be a common circuit I had the same problum last year and had to replace the wires.
Should be the same circuit for parking/tail/dash lights
If a car's lights are not working properly, the fuses should be replaced. The light bulbs should also be replaced if needed.
Should be parking/tail/dash lights on a common circuit
If the night running lights have failed the bulbs should be checked. Find the bulb housings and remove the parts. After the bulbs are replaced check the lights.
The oxygen sensor is "done". It should be replaced.
If you have replaced the brake light bulbs lately check that you used the correct bulb. Some rear bulbs should be the 2 filament type and if a 1 filament bulb is used the lighting circuit shorts causing odd behavior.
Check fuse for parking lights--should be same circuit could be burnt out bulbs could be bad switch could be dimmer rheostat
Should be on same circuit as other brake lights
If you get sparking in an electrical switch there is a loose connection or short in the circuit. The switch should be repaired or replaced.