AC does not cool when stopped-air conditioner blows warmly when idle

There are several reasons why a car’s AC is not cooled when stopped, but only when moving. The most common reason is that the condenser cooling fan is not working. Cooling fans are often shared by radiators and condensers, but it’s important to know that there are two separate fans. The reason a bad cooling fan can have a significant impact on AC is the fact that the heat from the refrigerant (Freon) is normally cooled as it passes through the condenser.Therefore, even if the condenser fan is not working, it may not affect the AC while the car is working. Move at highway speed.. This is because the air passes through the condenser as you drive on the road, eliminating the need for a fan. When the car is stopped, the condenser relies entirely on a cooling fan to cool it. The cooling fan may be working, but it may be too slow to cool the condenser sufficiently. To check the motor, you can use a test light to make sure the power and ground are connected to the electrical plug. If power and ground are present and the motor is not functioning, the motor is open circuit. If the cooling fan motor is worn, it may be started temporarily by tapping the electric fan motor with a small hammer or wrench. If this does not cause the fan to spin at all, the motor will need to be replaced. This is another way to make sure you are receiving the power needed to operate. Also note that the cooling fan can start at any time (the engine may run off). Be careful not to get in the way of the blade. Please note that if the cooling fan motor does not work, the fuse may also be blown. Therefore, if the fan is not powered and the motor is locked, the fuse must be replaced when the fan motor is replaced.

Other causes of car AC not cooling when idle or stopped   

1. The car may be overheated-something other than a cooling fan.
2. If the car is overheated, heat transfer from the radiator to the condenser can change efficiency.
3. The AC compressor may not be pumping well at a slower RPM (revs per minute).
4. The expansion valve may not be adjusting the refrigerant correctly.
5. The fins of the condenser may bend or the condenser may be blocked by foreign matter.

There is a special condenser fin comb to straighten the condenser fins. But in my experience, bent condenser fins are not a very common problem. A more common problem when you drive in the countryside is pollen that accumulates over time during the fins. Garbage from the road, where a plastic bag or piece of paper blocks part of the condenser and reduces performance, can occur anywhere. When I was working as an auto technician, many customers were worried that the AC wasn’t cooling, but it wasn’t noticed that the car was overheating, even though the thermometer was fixed. It’s funny.