1996 Plymouth Voyager dash board lights

Electrical problem
1996 Plymouth Voyager 4 cyl Automatic

when I am driving my dash board lights including gas, gears. Mileage, speedometer, etc. It just shuts down it doesn't interfere with the driving but it wouldn't pass inspection also after a while they all do come back on while driving or the next time you start the van. Also my lights that tell me the circulation of the heater defroster etc. Flash