So it’s freezing here and the passenger side heater seems to work fine, hilariously it defrosts half the windshield. The drivers side up/down button for adjusting heat does seem to work because it will select the drivers side climate away from the passenger side, it just doesn’t actually change the level and it’s stuck on low. Both the up and down arrow will do this, so if that button is working what is keeping it from trying to increase the heat?

Passenger side works great, can go all the way from low to high and back down. The fan does seems extra loud on high setting like it’s running into a clogged filter or blend door or something but I haven’t changed that filter since this summer and the wife (it’s her car) vapes like chimney so maybe it just needs changing again.