We used to drive an older car.
During a road trip during the summer we ran into a problem with our heater not turning off at all.
Imagine driving on a very hot day and your car is pumping out hot air non stop. Unfortunately we could not get the car into the shop as the small town we were in did not have one. So in order to make it to my friend’s graduation my husband had to install a shutoff to the ventilation system in our vehicle when we stopped for the night to be able to make it to our destination before we passed out from heat exhaustion. He used a coat hanger up to close the vent to stop the warm air from blowing in through the car. We were able to make it to the graduation. We ended up staying an extra day just to get the car into the shop so we could control the heating system the right way. The HVAC specialist that worked on the car said this was a common issue with this vehicle and although it is a simple fix most people just suffer through it. He laughed when he saw the coat hanger under the dash as that was the most ingenious way he had seen to temporarily fix the problem until a HVAC repair could be made on the car. He fixed the heater vent and we had no further problems with it until the blower went out. So many factors go into the maintenance and functioning of a vehicle HVAC system.