Purchased a well used 2001 Suburban 5.3 half ton , from a individual . The ABS brake light was on and he said he had it disconnected because the sensor was bad. Truck stops fine as rotors and pads have been replaced within the last 20,000 . This morning at about mile 80 of my ownership the red brake light comes on and starts flashing on the dash and the buzzer is going off like when the door is open with the key in the ignition . Brake fluid level is fine and there does not appear to be any leaks.When the truck is stopped the light is still flashing on the dash but the buzzer stops. Buzzer starts again at anything over 5mph in reverse or forward. Is this related to the ABS sensor issue or do i need to look somewhere else? Truck has 189635 miles. Thanks for your thoughts