Your brake warning light indicates one (or both) of two things:  low
brake fluid or a problem when you try to apply the brakes (the brake
system is pressurized) If the light is staying on, check the brake fluid
level. If not low, check to see if the Low Brake Fluid sender (in the
top of the master cylinder) is working right.  If the fluid is low, top
it off, and then figure out where the fluid is going.