I have read about the problems with this model not cooling very well and certainly mine is no different in the 5 years I have owned it. Took it to the dealer last year and they said it cooled down 20 deg below outside air and was ok(I'm sure they just cranked it in the shop). This is not my everyday truck. Recently I took the time on a trip to put a temp gauge in the vent. Outside temp was 88. At highway speed, inside truck was 79. Vent temp varied at norm to 75-76deg and on max after 5min to 72deg and after 10 min to 70 deg and stayed there. However, when stoping and truck going to idle the vent temp went down to 60 deg. Going back to highway speed, vent temp would go back to mid 70 again. Normally I think this scenario to be just the opposite,cooling only when driving fast. Does this give anyone a suggestion of my ac problem?