1988 4.3l

I have a 1988 4.3 liter. The 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.