ac and heat work at same time

Hello, Dave here, contributing to RepairPal and providing expert advice since 2010. I cannot say I know what you are meaning about AC and heat working at the same time. Perhaps explain further? Your air conditioning system will operate while the heat is on - this is entirely normal. But it will not blow cold air if heat is desired. The air conditioning system acts to dehumidify the interior of the vehicle regardless off desired temperature. Are you experiencing one side of the dash hot and the other cold? If so, you could have a faulty temperature blend door motor that changes the air flow in the dash from hot air created to cold air. Your vehicle may be equipped with a "dual zone" system, allowing individual temperatures on each side https://repairpal.com/auto-repair-near-me Click the link or call us at 877-913-1554. We'll gladly find you a certified RepairPal shop in your area.