Brake lights My turn signals work but my break lights do not what could be the problem

Usually if the third brake light works but not the regular brake lights, the problem is inside the turn signal switch.

The brake lights work from a switch at the top of the brake pedal under the dash. They can get out of adjustment or break which results in a situation as if the brake pedal is depressed all the time. Turn signals only work with the ignition on. The switch is just a device that allows the current to either the left or right lights so if the lights are not working it will be either the switch contacts or the flasher can

I can almost 100% guaranty the turn signal switch is the problem. Power for the brake lights starts at the brake switch. power then splits from there and the third brake light gets power directly from the brake switch. Since the turn signal and the brake lights are on the same bulb power for the brake lights is routed through the turn signal switch. the switch depending on what position it is in will allow brake power or turn signal power to there respective left or right brake/turn bulbs.

If you hold your foot on the brake pedal and wiggle the turn signal and or play with the hazard switch the brake lights will almost always intermittently start to work. this will confirm a bad turn signal switch which is pretty common on GM vehicle with this style setup.

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sounds like you have a bad turn signal switch.

If the third brake light is working than we know the fuse is good and the switch is good. The third brake light bypasses the turn signal switch. If the rear turn signals are working than we also know that the wiring from the switch to the rear bulbs is also good. The brake lights and the turn signals are on the same bulb so the turn signal switch is what determines if the bulb gets power from the brake light switch or from the turn signal flasher. If the switch is bad usually the first thing that stops working is the brake lights.

Typically you can wiggle, jiggle, pull, push on the switch lever with you foot on the brake and get the brake lights to work. Sometimes turning the four way on and off several times will also get the brake lights to work. If this is the case than a new turn signal switch will solve you problem.

If you have any questions let me know!

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

PROBLEM COULD BE TURN SIGNAL SWITCH. MOST CARS TURN SIGNAL SWITCH AND BRAKES LIGHT SHARE SAME CIRCUIT.

PROBLEM COULD BE THE THE MULTIFUNCTION SWITCH. IT CONTROLS HEADLIGHTS, TURN SIGNAL LIGHTS AND BRAKE LIGHTS SHARE THE SAME CIRCUIT.

it could be a turn signal relay that is stuck. do your turn signals work, I know that sounds weird but for american cars the turn signal interrupts the brake light so if ur turn signals are not working properly it might be, also there is probably a brake/hazard relay

Replace the turn signal switch. Bad contact inside causing a crossing of the circuits. When the turn signal is applied it should open the brake light circuit allowing for just the signal to work. Doesn't sound like the switch is doing it's job.

I know what it is. I have the same problem. Try, when pressing the break, pulling your turning signal lever towards yourself, but not all the way to turn on the brights. If your breaks light up then you need a new turn signal switch. Part of the switch disables the break lights when that flasher comes on, but when it goes bad, it wont let the lights com on at all.

Have you checked your brake light fuse? If it is good do your rear turn signals work? If you have turn signal and no brake lights it is probably the turn signal switch these are a common problem and your power for your brake lights goes through your turn signal switch. Sometimes it is actually the hazard switch that melts but this can not be serviced alone. If you have no rear turn signals and no break lights it could still be the turn signal switch but is more likely to be a wiring problem in the rear usually trailer wiring T connections. Chiltons has wiring diagrams in there manuals but they are not always accurate. Let me know if I can help you further and please rate.