[LazzyBumm]

I have an 08 with about 170k miles that only blows hot/warm air when it’s set to bring air in from the outside and I floor it. Any other time it blows cold air. When I switch to recirculating mode the AC snowflake button blinks a few times and then goes solid and blows cold. All of the vents seem to blow as they should including the defrost vents, it’s just not making heat. I just fixed an issue with the coolant crossover pipe gasket leaking, but the issue still persists. I’ve seen things about the blender not working or maybe the recirculating actuator being the issue, but they don’t seem to have the exact same issues as me and I don’t just have extra money to throw at every possible issue.

 

[boomer]

Flooring the accelerator will temporarily disable the AC. The compressor clutch is disabled to keep the engine power going to the wheels rather than cooling the cabin. Probably not much of a difference, but it is a "feature" of the car. The reason you may not notice is the air is probably already cooler / less humid when you have it set to recirculate.

You should be able to check the temperature of the hoses going to the heater matrix (flow and return). If they are not hot, you probably have a blockage. Also, if you turn the heater controls you can usually hear the blend door actuator move on mine. If there is no sound or you hear a clicking noise, the actuator may have failed. Another option is to remove the panel so you can see the actuator and confirm visually that it actually turns.

Hope this helps