got a 1998 Ford Ranger XLT and the ABS and Brake light keep coming on. Brakes don't seem bad but they don't seem perfect either. I purchased an ABS sensor for the rear differential from ebay. Installed it and drove it hard for 10 minutes. Lights didn't come on and brakes seemed fine. Parked it, and got back in it and drove down the road. When I hit 55, and each time I hit 55, the speedometer goes crazy. It drops down to zero, hops back up to 20, drops to zero, hops back up to 55, and it feels like its going to stall. It was a scary ride. I go home and I replace the new sensor with the old one, and everything is back to the way it is, with the ABS light and the Brake light coming on when I step on the brakes hard. So does this mean the back sensor is fine and one of my front sensors needs replaced? I don't want to guess again.