Chrysler Repair: Over heating, cooling fans, air flow

Question
  I have a 2002 Town and Country.I have have replaced the thermostat but I am still having the same problem. the van will overheat if you exceed 50 mph, the longer you stay above this speed or more the temp keeps rising. But if you put the car in neutral and start to coast, it starts going down to normal and does fine if you stay under 50. Thanks in advance.

   William

Answer
Hi William,
Do the cooling fans come on as the temp rises? Pull over and check for that to occur or listen for them. If not it is probably the fan relay has failed but check the fuse #27 as well. It may be that the radiator flow-through may be impaired by build-up of crud in the tubing, and also look through the radiator fins at a light placed on the backside to see if the air flow is impaired by dirt/leaves. Those are the things to consider first.
Roland