Chevrolet Repair: abs light, wheel sensors, switch centers

Question
Hello Van, I have a 1990 G.M.C. K-1500 X/C 4X4 TRUCK .. I am having a problem with the RED abs/brake light (one light for two functions) either staying on all the time or blinking 10-times continuesly...I have changed all the brakes, rotors, drums and wheel cylinders AND NEW BRAKE FLUID.. I even tried another abs module but the light came back on I ALSO CHECKED THE EMERGENCY BRAKE SWITCH AND THAT APPEARS FINE ... This a.b.s. unit only controls the back brakes..I do-not see any front wheel sensors or any sensors on the differential..This light has been on since I bought the truck a year ago and it is annoying... WHAT DO YOU THINK THE PROBLEM IS,THANX TONY....

Answer
Hello Anthony,
It is possible the front pads were changed, and when the pistons were pushed all the way in, they hit the brakes, and uncentered the proportioning valve switch mechanism.
it could just need one end bled till the switch centers and turns off the light.
Van