What are the reasons for the intermittent stoppage of a car's air conditioning cooling function?
3 Answers
The main reason for the intermittent stoppage of a car's air conditioning cooling function is compressor issues. The compressor in the air conditioning system is equipped with a clutch, and the compressor only operates when the clutch is engaged. If the compressor is damaged and cannot switch to the engaged state, the air conditioning will not cool. If the refrigerant is sufficient but the air conditioning still does not cool at all, it may indicate that the compressor has stopped working, and you should consider repairing or replacing the compressor. Other possible causes and solutions: Air in the system can also lead to insufficient cooling. Once air enters the air conditioning system, it can cause excessive pressure in the refrigerant lines or poor refrigerant circulation, which similarly results in insufficient cooling. This is mainly due to degraded sealing of the cooling system or incomplete vacuuming during maintenance. Removing the air from the system can resolve the issue. Insufficient refrigerant. Apart from normal consumption, this is mostly caused by minor leaks in the system. If there is insufficient refrigerant in the air conditioning system, the amount of refrigerant sprayed into the evaporator from the expansion valve will decrease accordingly. This leads to reduced heat absorption during evaporation in the evaporator, resulting in lower cooling capacity. Simply repair or replace the leaking components and replenish the refrigerant to fix the issue. During high-speed driving, the rapid engine speed increases the pressure in the air conditioning system. The compressor may stop operating due to excessively high pressure control, causing the cooling function to pause temporarily. In this case, slowing down the car to allow it to cool down will restore normal operation.
When I repaired my car myself, I encountered intermittent air conditioning cooling issues. This is usually caused by a refrigerant leak due to insufficient levels, and the system will automatically shut down for protection when the pressure is too low. A sticking or non-engaging compressor clutch can also cause the cooling to turn on and off intermittently, especially under heavy loads during long-distance driving. A blown fuse is even more common, as a circuit interruption directly triggers the protection mechanism. If the condenser fan is broken and heat dissipation is poor, the air conditioning will overheat and stop working, resuming after cooling down for a while. Additionally, a frozen evaporator can block the air ducts, causing the cooling to stop. I recommend checking these key points first, such as listening for fan operation or feeling the temperature of the pipes, as troubleshooting minor issues yourself can save money and hassle.
As a long-distance driver, it's quite common for the air conditioning to stop and restart. In older cars, voltage instability or alternator issues can cause the compressor to shut down as a self-protection measure when overloaded. Aging sensors like thermostats can become inaccurate, sending erratic signals that randomly turn the AC on and off. Severe dust buildup on the condenser leads to poor heat dissipation, interrupting cooling during high temperatures. A clogged expansion valve causes unstable refrigerant flow, resulting in intermittent cooling. Additionally, rusted relay contacts can cause intermittent failures due to poor connection. When this happens, I usually turn off the AC for ten minutes before restarting. If that doesn't work, I head straight to the repair shop - never push through in hot weather as it compromises driving safety.
