If the coolant sensor is bad, cou it shut my Jeep off and not let it click over?

Not the sensor .. Hands-on testing by qualified personnel will be required.

Hello, The coolant temperature sensor can cause your vehicle to stall, but typically it can be restarted repeatedly without issues. It would also cause the gauge to flash over to full hot. If the sensor is bad, you should replace it either way. This is especially important due to the age of the vehicle.