I replaced the battery in my car back in April. After I replaced the battery the ABS system worked fine. Then one day I drove the and made a few stopped. When I got home I parked the car on the side of the house. When I went to park the back in the garage the ABS and Brake lights were on, but the brakes felt fine. At first I thought it was just because the car was hot so I let it sit for about 2 hours, when I went back out and stuck the key in the ignition the pump motor started running and the lights eventually went out. Now the problem I am having is on Fathers day there was a local Ford show. When I went to get the out and go the pump motor was running but the lights stayed on and the pedal was as hard as rock. I have had this problem off and on for about three years now. In the process of trying to figure it everything with the ABS stopped working. I replaced the pressure warning switch about a year ago and just replaced the relay to try and fix the problem.