99 no power

I have a 99xj 4.0 and was running great. After driving and parking went to restart and nothing no lights, radio, nothing. Took out and checked all fuses that went to ing starter batt etc.. put all back in and it fired right up radio had reset that was it. Drove to work the next day no issue. On the way home ( 7 miles) about 3 blocks away check gauges light comes on and volt gauge is pegged at 19. Got home fine shut it off tried restarting nothing again. Went out in the morning turned right over no issues. Ive been reading could be a Crankshaft position sensor giving bad reading when jeep reaches temp. Also alternator, battery. Going to look at it today or tomorrow any help is appreciated.

Those are classic symptoms of dirty battery terminals. Take them off and clean them with a battery brush and baking soda and water solution. Rinse with clean water and reconnect.