My brake lights on my car won't work what are the possible reasons

You might have a dead short in the wiring, or the frame ground could be coroded

Get a test light and check the brake lite switch.one side should be hot the other side should not.find the hot side then put test light on the other side and press brake pedel.if the test light does not light the switch is bad.not knowing what the vehicle is you may have a bad turn-signal switch.your brake lites go through your turn-signal switch as do most cars and trucks.

Check the brake light switch and make sure you have power and ground at the lights

I would guess that the stop light switch is bad. That would be the little button above the brake pedal.

Carefully remove the plug from the switch, and use a jumper between the terminals, and see if the brake lights work.

If they do, it is that "button". a.k.a. stoplight switch that is bad.

This answer was edited by the_mekanic 193 days ago.

Reason: ed