My 3rd brake light stays on, even when the key is out and the car is empty. Though when i step on the brake, the other 2 brake lights do NOT work at all. Im stumped. i've checked my fuses but I have not checked the brake light switch. I will once i'm out of work.

since the 3rd light will not shut off, it has completely drained my battery.

i am terrible with car electronics so does anyone have any suggestions on what to do?

 

Sounds like there is a short in the bulb for the 3rd brake light, check that one first. The brake lights don't need the key in the ignition.

 

GM? if so, get a new switch, and then check to see if the rear bulbs are blown out. the switches on them have two outputs, one for the CHMSL and one for the rear lights.

if its a VW....its under recall.

if its a ford, i can honestly say i havent seen a switch fail, but the M/C bushings do get worn causing that problem.

if its a honda, make sure that the rubber bumper on the brake pedal shaft is still there, most likely it dry rotted and fell out, leaving the plunger in the brake light switch stuck out.

 

right on the nose. it took me a while to figure out that shit was missing.

 

seen it many times. i have a set of the rubber bumpers in my toolbox for that reason only!