I have a '01 Chevy Blazer (S-10 version) that has a Brake light constantly on along with the ABS light. They both come on at the same time. They don't come on right away when I start the car up after sitting for a while. But it seems when the engine is warmed up that is when they both come on at the same time. When it is extremely cold (like January in MN cold) they don't come on at all.

As you can tell I have learned to ignore them because both regular braking and ABS braking have seemed to work just fine. But I am now thinking about getting rid of it and would like to figure out how to fix it. Will this be a costly repair?

Hi there
Your abs light could be caused by a bad resistance at one of the abs sensors which will cause the abs light to come in and stay on you need too check the volts at each abs sensor at the wheel side of the cable I:e the end that goes to the wheel as for the brake light is it just an wear indicater light hope this might help
Bob

Have a shop hook the truck up to a diagnostic scanner that will let them read each of the wheel speed sensors. If one is reading erratically, it thinks the wheel is slipping when it's not and relays this information to the computer.