with temps 40-50`s with the hvac set to manual, on a sunny day with lots of sun on windshield and dash, my floor heat turns to cool. I love warm air on my feet until temps get well into the 70`s. this is a 2018 sil with auto climate control. Oh, lol, i can push the fan button to off and have no air anywhere. Is this normal or am i not understanding the owner manual? I did read that the little thingy in middle of dash board controls the hvac.