If it's cold outside do you want cold air blasting when you get in your car?
You are low on coolant to the heater core.
Coming out of the vents around 43 degrees
because you need to keep warm when it is winter and other times when it it cold
A.C. circulates air(just like a fan) and turns it cool.
Simple, you ac does not blow cold air even though you have it turned on and the temperature set to cold.
The heating system doesn't get heat until the car warms up and the thermostat opens.
Sounds like your compressor is locking up.
Yes, and it can also make your car to over heat
if car is blowing cold air, you need to check the thermostat,the heater core, and the heat control. the coolant will not blow cold air unless there is no coolant at all in engine,then you have bigger problem anyway
If the car is setting in the sun.Heat builds up in the ducts. With my car, it was Heater matrix clogged with radiator sealant. The workshop cleaned it and it's start working fine!
The compresor is completely frozen.
Check for low coolant