Our 1998 Town & Country indicates it is overheating when it idles for more than 10 minutes. When the car is moving, the idiot light does not come on and the temperature gauge indicates normal temp ranges.
Generally when a vehicle overheats while idling and cools down when moving it’s a sign that the cooling fan is not working. This is easy to confirm by just looking at the fan(s) while the car idles. Some cars have two fans, one thet runs whenever the AC is engaged and the other when the engine warms up. I’m not sure about the '98 T&C.
Suspect parts include the fan itself, the temp sensir that turns it on, and the fan relay.
Check to see if the cooling fan(s) are working.