Dash brake warning light on

I have a 1988 Chevy 4.3 liter. The warning brake light on the dash will not shut off. At first I thought it was the parking brake got pushed a little bit somehow but I released that and the light is still on. Could be that its just and old truck and the light is just on for no reason? Anyone had this happen? It also will not idle when its cold out like below freezing. It idles for like 3 minutes or so then dies out everytime. I love the truck though.

Not sure if it's the same with these trucks, but in my lincoln I had the same problem, after I'd turn really hard the parking break light would turn on and stay on. I was told to check the brake fluid and top it off if it needed it and nonetheless, solved the problem.

if your brake fluid is not low and your brakes are operating normally you probably have a anti lock brake malfunction. If the anti lock brake Control Module detects a malfunction it will store a code and turn the light on. If you remove the negative battery cable for a few minutes or disconnect the control module (next to master cylinger) it should reset the code. If the light returns you have some sort of problem. Sometimes in the winter it will come on if you are driving through snow with your tires spinning and hit the brakes. You can get the trouble code by using a jumper wire jumper terminal H and A. H is on the bottom row, anf the second terminal from the left. A is on the top row and is the first terminal on the right. turn the key to run position and the light will flash to give you a trouble code. If I rememebr correctly you count the flashes and add the two number up to get the code as opposed to them being the digits of the number, I am sure if you get the code someone on here can help you out further, However i would try reseting it first

I had a similar problem after a shop installed a new carrier in the rear differential. Parking brake light wouldn't go out. I disconnected the negative battery terminal for a minute and when I reconnected the light stayed off. No problems and its been several weeks.