Q: Overheats When Blowing Warm With Heat & AC But Not When Blowing Cold AC

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2006 Mercury Mountaineer overheating when heater or AC blowing hot air. When the heat is on it starts to overheat. Once I turn the heat completely off, it cools back down. I turned on the AC and it was fine. Then, with the AC on I turned the temperature up to 90. It blowed the hot air but then started to overheat. When the AC is on and set to blow cold air, it's fine. So, it's only happening when the temp is turned up to get heat whether it's in heat mode or AC mode. Any ideas?
Autozone pulled these codes... P0446 P0196 P0506 P2004 P2005

My car has 153000 miles.
My car has an automatic transmission.

Hello, thank you for writing in. There are so many different codes being triggered, that it is unlikely all of these systems are having issues at once. We need to focus in on the fact the engine is overheating at all. You will want to check the level and condition of the coolant and the overflow tank. If the level is full then you may have an issue with the thermostat, radiator cap, or water pump. These can all be tested and changed relatively easily. If the main cooling system is okay, you will want to look into the heater core and climate control module. For more diagnostic help, contact our service department to schedule an appointment.

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