I think my heater core is a little clogged. My heat isn't the greatest. But this week while on a trip up to the mountains, I noticed my fresh air switch slides to the left at highway speeds. I pushed it back to recirculate, but it moves back to the middle.
I guess I won't get the best heat with that open half way.
I think this is a door that lets in fresh air, right? Is there a spring or something that keeps it closed? Anyone else have/had this problem?