My 98 TJ has a problem. The instrumental panel i.e. speedometer, tach, airbag light, etc. Shuts down sometimes when I hit a bump on the road and a few times it just shuts down while riding on smooth pavement. When this happen, the speedometer and tach needles drop to zero, the airbag light comes on and the mileage stop counting. The only way I can get it back working properly again is by tapping the top of the dash ( directly on top of those things ). Any ideas? Electrical problems? Please advice, Thank you!