AWOL

Driving today and noticed my heat getting cooler. Looked at the dash and the outside temp kept changing, but ranging from 40 (which it was) to 80 degrees. When at 80 degrees, my heat cooled down, but when it went back down to ~50, it warmed back up - even though it was set at 72 degrees.

And by the end of my trip, it read the correct temp and heat was fine.

Whats the correlation, if any?

Thanks