My left tail light doesn't work but when i hit my brake the light works. I changed the bulb and checked the fuses. I'm thinking its a wiring problem but not sure.
Tail light on 1992 Dodge W150
If you can get an automotive test light you can try to figure this problem out by, taking the test light and finding a good ground on or near the rear of the vehicle. Then remove the bulb and have someone step on the brake. In the bottom of the socket there should be 2 contacts. ( the ground contacts are usually on the side ) Touch the test light ( with the brake pedal pressed ) and determine which contact is working for the brake light. It should light the test light. Then have someone turn on the headlights and touch the other contact. If it doesn't light up the test light, determine the proper color of the wire by tracing it back from the bulb socket and then using the test light, probe the wire back up to the front of the vehicle until you find power and then repair the circut.