Do you have the 4.0L?
On my LTD the coolant light has never been on and the needle is pretty much smack dab in the middle of the gauge.
I would double-check what the manual states when the light comes on, but maybe the coolant level is low and needs a top up.
Have you noticed any leaks on the pavement or if you pop the hood?
'08 Town and Country LTD 4.0L
Built Sept. 2007, took delivery Dec. 2007
STATUS: Returned March 1, 2010
48,500 kms on the odo
Brilliant Black w/ grey leather and suede inserts
MyGig, NAV, VES, Trailer tow, Power 3rd Row
Sunroof and Swivel n' Go