Chrysler Repair: 96 caravan overheating, dodge grand caravan, windshield defroster

Question
I have a 96 dodge grand caravan that overheats only if I'm in idle mode to long, or if I'm running the air conditioning. As long as I'm moving the van does not overheat. Just drove it 400 miles  round trip.

Answer
Hi Troy,
Are the low and high speed fans working? Those are key cooling devices for when you are idling and using the AC. In fact the fans will always come on when you have the AC in play if everything is OK. When you aren't using the AC but the temp is rising the slow speed fan should come on at around 220F and the high speed should speed up at 230F temp of the coolant as measured at the top radiator hose manifold on the front of the engine. So try asking starting the AC or the windshield defroster (which also uses the AC) and see if one fan at least starts immediately. It may well be that the fan relay which is what actually powers the fans has gone bad as this solid-state device had a pattern of failure that actually caused there to be a recall for replacement in the latter half of the 90's vehicles. So if you aren't getting any fan action I would check with the dealer for the recall possibility of having it replaced for free if that is the reason. The relay is located in the engine compartment, on the left side frame rail just to the rear of the left side of the radiator.  Otherwise, you may just need to flush the cooling system to improve the heat transfer characteristics of the radiator core.  
Please let me know what you observe and whether these suggestions are helpful.
Roland