What Causes the Air Conditioning to Stop Cooling After a Car is Exposed to the Sun?
3 Answers
When the air conditioning in a car stops cooling after being exposed to the sun, it is usually due to a malfunction in the air conditioning variable solenoid valve. The solution is to replace the air conditioning variable solenoid valve and clean the pipeline before refilling the refrigerant. Below is some relevant information about the air conditioning solenoid valve: 1. Introduction: The air conditioning solenoid valve is a key component that regulates the cooling and heating functions of the air conditioning system. The solenoid valve consists of an electromagnetic coil and a magnetic core. When the central air conditioning system starts, the electromagnetic coil generates an electromagnetic force that opens the valve, allowing the refrigerant to start working. Once the set temperature is reached, the electromagnetic coil is de-energized, the electromagnetic force disappears, and the refrigerant circulation is shut off, thereby regulating the temperature. 2. Composition: The electromagnetic part of the air conditioning solenoid valve consists of a fixed iron core, a moving iron core, a coil, and other components; the valve body part consists of a slide valve core, a slide valve sleeve, a spring base, and other parts. The electromagnetic coil is directly installed on the valve body, and the valve body is enclosed in a sealed tube, forming a simple and compact assembly.
Last time my car was parked in the sun all afternoon and the AC wasn't cooling. Later I found out the compressor clutch was faulty. When the engine bay gets too hot from sun exposure, this iron component that transfers power can seize up and slip, preventing refrigerant circulation. Additionally, a radiator clogged with dust or willow catkins severely impacts heat dissipation, and insufficient fan speed can cause the high-pressure pipe temperature to skyrocket. The worst part is when AC line pressure gets too high, the system automatically cuts off the compressor for protection. I remember one time just recharging the refrigerant fixed it, but later learned the condenser was leaking. My advice: first pop the hood to cool things down, try driving at highway speeds for ventilation. If that doesn't work, you'll need to get the pressure tested.
I've fixed quite a few of these issues, and hot weather is when problems most frequently occur. Refrigerant leakage is the number one culprit, especially in older cars where rubber seals harden from sun exposure and start leaking. An air filter clogged like a brick will make you feel weak airflow with no cooling - last year I helped my neighbor replace theirs and it became instantly chilly. Another hidden killer is expansion valve icing; when the evaporator temperature gets too low it triggers protective shutdown, but turning on the heater briefly can restore cooling. By the way, don't blast the AC at lowest temperature immediately after entering the car - first ventilate by opening windows for two minutes before activating AC, which is gentler on the compressor.
