There could be a severed connection somewhere along the line, or it could just be a blown fuse
Fuse
either dimmer switch or blown fuse If you are saying that the tail brake lights are working but the third brake light is not....It may be a defective turn signal switch in the steering column.
Tail lights. Brake lights. Backup lights. Signal lights. License plate lights.
i got a 2006toyota highlander my tail lights dont work but,every other light works please help me
Try checking the tail light relay.
Brake lights and turn signals are on a separate circuit from the tail lights. Tail lights are on the same circuit with the dashboard lights. If the dashboard lights aren't working either, check the fuse. If they ARE working, check the headlight switch.
If the headlights are on and brake lights work but not the tail lights, it is possible there is a short in the electrical wires. Another cause for this could be that the tail light bulbs are burned out. Most vehicles have more than one bulb inside the tail lights to control different lights at the same time.
See sources and related links below for 1993 Dodge Shadow tail light, brake light and turn signal light bulb part numbers.
Look for a fuse labeled TAIL LIGHTS. There are 2 separate circuits, one for brake turn and flasher and the other is for tail lights.
Headlights? Brake lights? Tail lights? Signal lights? Courtesy lights? Dash lights? Check engine lights? Need more info please.
I found it easier to use the wires to the tail lights on the tractor.
Try your fuses