So this morning i start my truck and my brake light wont turn off. This is the first time that this has happened.It ws really cold out this morning(-32) and i was running late so i didnt bother to see if it was maybe low on brake fluid or something.
Does anyone know why this would happen and what else could it be?

 

was the brake pedal pressed a little bit? whenever it is cold and humid, mine wont come up all the way. its drained my battery twice from being on overnight. now i have learned then when the its cold and wet,i need to manually pull the brake pedal back up

 

I will see if its down, but i dont think it was.

 

I never had this problem with my blazer, but it did happen on a camaro I had. I don't know if the design is the same on the blazer, but I'll describe how it was on the camaro, and maybe it will be similar enough to help.

Under the dashboard, near the top of the brake pedal lever, there was a little black box with a button on it. When the brake pedal was up, the button on the box was pressed in and the brake lights were off. When you press the brake pedal, the button came out and the brakes turned on. What happened to me was that the little box came loose, and thus the button was permanantly not pressed, so the brake lights were always on. If you can secure it back in place, the problem will be fixed.

 

typically when the brake lihght comes on you have a leak.

 

rjck1979, I just realized....I'm not sure if you are asking about the brake lights on the back of your truck, or an indicator light on your dashboard.

 

Maybe there is a leak, i checked the brake fluid this past thursday and it was very low so i topped it up and have been monitoring it everyday. im hoping its not a slow leak. I dont know any history on the truck as i just bought it this past september with 79500 km on it.Plus ive only put about 1500 km on it since buying it as i only will be driving it in the winter and when it rains in the summer as i have a 1995 camaro that i love soo much. thats for all the info everyone.

 

SOrry, I should have gone into more detail.
Relax though no harm done.

Two things cause the brake light to come on, generally.
1) a leak, adding fluid wont make the light go out, the leak is still there.
2) worn out brakes will also cause the brake light to come on. What hapens is the pads are worn out so it takes more fluid in teh lines, this lowers the brake fluid level in the res. thus tripping the brake light for "low fluid".

Since you added fluid, and the light went out, you will need a brake job soon. How soon depends on how you rdrive. If you hear grinding, you needed the brake job yesterday. Dont fret too much though, you have to replace the rotors anyways, its just that now oyur out of pad nad the rivets holding the pad on are whats stopping you by diging into the rotor. The noise will get worse, and it you let it go you will be replacing a caliper or wheel cylinder.

I missed th part aobut the year of your truck. However inspect the inside and outside pads ont eh front, jack it up and use a flashlight. If you have disc brakes int eh back do the same. If you have drums, you will need to take the tires off to inspect the pads. And its best to just go ahead and replace them while your there.

I'll be glad to give you some tips if you plan on doing hte work yourself. If not I'll save the typing for another day. Let me know.