Hy Tommy, the shaft which activates the brake warning light inside the combination valve has shuttled over because of a difference in pressure between the two separate braking circuits. Some combination valves have electrical connections which can be unscrewed, if you have good access you could see if your connection will unscrew, if it will unscrew it and look down inside the switch, you should be able to look down inside and see where the shaft has moved one way or the other, the shaft has a low area on it which should be in the center of the switch port. I have had some success putting a small shaft down the hole, applying moderate down force and dragging the shaft back to its centered position. I hope that works for you, good luck. There are tools available that can be put in place before you bleed the brakes which hold the shaft centered while you bleed the brakes.
