I'm thinking I have an issue with my antilock brake system, but not sure. This a 4 wheel drive 1996 S10 blazer that has had the transmission recently rebuilt. What happens is usually first start in the morning I take off and the Antilock brake light comes on and the truck won't shift out of first gear, the gauges don't appear to be working,(speedometer). I stop take off again and it will eventually shift into second and all of the gauges work, the speedo jumps to the current speed. The truck runs great and shifts fine the rest of the day, eventually the antilock break light goes out and won't repeat until the next day. Any ideas on where to start??