I have a 2004 Ford Freestar with only 82,000 miles on it. I took a trip last week and noticed the A/C wasn't working properly. It gets nice and cold on the passenger side but the driver side only blows slightly cool air, especially on in town driving. When I was on the freeway, it worked fine on both sides. Why does the driver side not blow cold air during in town driving? It blows good but it's not cold.