I have a 2001 5.3 silverado and the speedo jumps around after I drive for 30 or so miles. It works fine on short trips. Its like it has to get warm to start acting up. It will jump in 5mph. If I turn the truck off for awhile it will start working normal til I travel for alittle bit. Any ideas would be great!
Hello: Well I think most of the newer spedos are driven by a stepper motor right in the dash itself. The stepper motor is driven by the Computer which gets its info from a speed sensor. I have no idea where these things are on your truck, but if you have a service manual you will be able to locate them