1. Check whether the air conditioner compressor is activated. You can try to start the air conditioning, and then pay attention to whether the engine load has changed(speed and sound), to see if the compressor can be felt to start. In the past, it was possible to judge whether the flywheel of the air-conditioning compressor was started or not, but there is now a constant motion compressor, so it may not be accurate to watch the compressor flywheel. If the compressor should be started but not, repair the air conditioner compressor.

2. If the air conditioning compressor is activated and the air conditioning outlet has enough wind to blow out, and the wind volume will increase significantly as the gear is adjusted, then the air duct is probably no problem. It should be that the refrigeration refrigerant is insufficient and the air-conditioning system needs to be maintained. Removal system and reirrigation of adequate refrigerant.

3. If the air volume of the air conditioning outlet is obviously insufficient, the wind channel may be blocked. If the car's air conditioning system has an air filter, it should be a filter filter that is too dirty and needs to be removed or replaced. If there is no air filter in the car's air conditioning system, check to see if the air intake is blocked.