THis is a very common problem with this vehicle. MOst of the time its just a bad instrument cluster. However, the BCM and a few other things on that circuit can cause this problem. When the problem is occurring, perform the Instrument Cluster self test. Begin with the ignition key switch in the off position. Press and hold in the Odometer Trip and Reset buttons. Turn the key to the On position. Wait until the word CODE appears in the Odometer window, then release the buttons. A normal self test will step through turning all of the indicator lights on and off and sweeping all of the gauge needles. If this does not happen, the test has failed. Just be sure all of the inputs are ok to the back of the instrument cluster. There should be 12 volts on the Pink wire at cavity 2 and the Red/White Wire at cavity 11. There should be good ground available on the Black/Light Green wire at cavity 7 and the Black wire at cavity 13. The White/Black wire at cavity 9 and the Violet/Brown wire at cavity 10 are both Bus wires. Each of them should have approximately 2.5 volts. If these all check OK, replace the Instrument Cluster Circuit Board.