What Causes the Air Conditioning Not to Start When the Car Interior Temperature is High?
2 Answers
The reasons why the air conditioning does not start when the car interior temperature is high are as follows: 1. When using the air conditioning: The engine operates under high load conditions, and the air conditioning compressor increases the engine load. 2. Condenser: The condenser requires a cooling fan for forced heat dissipation, so the engine temperature is one of the important parameters of the air conditioning system. 3. Engine control unit: When the engine temperature is too high, the engine control unit will cut off the ground terminal of the air conditioning compressor relay to reduce the temperature by reducing the engine load. More information about excessively high engine temperature is as follows: 1. Blockage: System dirt blockage, internal blockage of the radiator tank. Machine blockage, such as a malfunctioning or damaged thermostat, or a malfunctioning water pump. 2. Malfunction: Air lock, engine malfunction causing high pressure in the cylinder to enter the cooling system. Poor heat dissipation, low cooling fan speed. Damaged fan shroud, dirty radiator surface. Cars with electric fans have a cooling fan activation device.
I encountered the same issue a couple of days ago while driving—the car was stuffy but the AC just wouldn’t blow cold air. This is quite common. It could be that the AC compressor has failed, the clutch isn’t engaging, or the belt is loose. Another possibility is that the refrigerant has leaked out; if there’s a crack in the piping, it can slowly leak. There’s also a chance that a fuse has blown—check the engine compartment fuse box for the one marked "AC." By the way, if the AC control panel is acting up, it can cause this too, like buttons not responding. With the hot weather now, the AC is under heavy load and more prone to issues. I’d recommend checking the simplest things first, like the fuse and refrigerant pressure. If that doesn’t solve it, you should head to a repair shop ASAP.
