Hot and Cold

We have a 2002 Lincoln LS. It has over 100,000 miles on it.

Last year we noticed, when driving it over 35 to 40 minutes, that the heat or cooling would change…for example…it’s 85 degrees outside, you have the interior set at 72 degrees, it’s doing just fine and then all of a sudden it starts blowing out hot…yes hot air…you have to shut down the system and open the window to get some of that cool 85 degree air. It also does the same thing when it’s cold…say 30 degrees, and you have your heat set at 70 degrees, after 35 - 40 minutes it starts blowing out cold air…

The repair people tell us they have to catch it while it’s doing it…the problem is they’re closed by the time we’re driving home and you have to make an appointment to get in, by the time it sets for an hour or so it quits doing it.

Help me if you can.

My guess it’s the control module, or the wires and connector that go to it.