Answer to: Why dont my brake lights workBefore clipping any wires, keep in mind that most older model year trucks have the same bulb filament used for both the brake function and the turn indicator function. For that to work, the brake wire runs to the turn indicator, so that when you turn on the flashing turn signal, it switches out the brake light signal for that side so that the two signals don't collide. So don't just check the brake light. Also check the turn signals. In my case, the brake lights didn't work but the turn signals did, so that told me the wiring to the bulbs was OK and the wiring running in the frame was OK and the bulb contacts were OK. So I assume I need to check the brake light switch, the fuse, and for a truck, any wiring done for the trailer hitch to make sure it is OK.