For car owners in the UAE, an air conditioner is a must-have as the weather tends to stay warm for the better part of the year. Not only does an air conditioner make driving comfortable, but it can also help you cool down when the car is parked. However, like many car components, it is prone to damage and may encounter issues such as malfunction, not cooling properly or only working when driving.
If the car AC only works when driving, there may be several reasons for this. We will go through the causes and fixes of why the car’s air conditioner only works when driving.
Car AC Problems
A non-functional or faulty car AC can be frustrating to handle. Particularly in humid regions, the common car AC issues can affect your overall driving experience. Pit stops are a normal occurrence during driving where the car usually sits idle. Additionally, during the visit to malls and places, people may need to sit in parked vehicles for some time.
Either way, if the AC is non-functional, heat can at times be unbearable in an idle car. Moreover, car colours affect the interior temperature and depending on the upholstery material and colours, the heat effect may be severe in some cases.
Car AC Only Works When Driving – Causes and Fixes
There are some car AC maintenance tips to help keep the unit in good condition. However, there could be several causes why a car AC only works when driving. Let’s go through them in detail and figure out the ways to overcome them.
FAULTY CONDENSER FANS
Defected condenser fans can be among the major causes when air conditioning only works when driving. Condenser fans help reduce the refrigerant’s temperature to ensure it condenses. Malfunctions in condenser fans can prevent this from happening.
A condenser fan can malfunction or is unable to turn on automatically can happen because of the following reasons:
- A faulty temperature switch
- A defective coolant sensor
- A stuck open car engine thermostat
- A faulty fan control module
- A dysfunctional fan motor
HOW TO FIX
Crank the car’s engine and set the AC to maximum temperature. If the fan is rotating, it indicates the fuses and relays are functional and in fine condition. However, the cranking method does not provide conclusive information regarding PCM and temperature sensors.
Therefore, you can use a multimeter to check the temperature sensor, bad relays, blown fuses and continuity in the fan’s wiring. Another considerable option to troubleshoot a fan motor is by using jumper cables.
Unplug the fan motor and use jumper cables to power it directly from the battery. If the fan runs smoothly, there are no issues. However, a slow-spinning fan indicates a fault. You may need to replace some car AC system parts such as relays, fuses, thermostats and sensors.
A faulty motor can either be replaced or repaired by a service professional. Moreover, as an added measure, try and keep a check on any loosening bolts or wire connections. You may also use a mixture of water and baking soda to remove corrosion from wires.
BLOCKED AC CONDENSER
If the condenser fan isn’t a problem, an outsource source may be the culprit. A clogged condenser, for instance, can be the reason car AC only works when driving. A damaged or clogged condenser can affect the air conditioner’s performance.
HOW TO FIX
Fortunately, a clogged AC condenser is rather easy to fix. All you need to do is clean the condenser and remove the clogging source. Be sure to use a clean cloth or a professional cleaning tool to avoid causing any damage to the condenser.
LEAKAGE IN AC
Leakages of any sort can also affect AC performance. The air conditioner might not function at all when the car is not in motion. If you encounter any car AC leakage problems, it is better to fix them at the earliest.
HOW TO FIX
To identify a leakage problem, you must first diagnose the car AC. It can be done with these easy steps:
- Check coolant levels and add more fluids if the levels are low.
- Examine the compressor belt for any signs of damage or if it has become loose
- Check air filters and see if it needs replacing
In addition to these, there are some other ways to fix car AC leak that can also come in handy.
DAMAGED/CLOGGED COMPRESSOR CLUTCH
A damaged or clogged compressor clutch can also be the reason why car ac only works when driving. The first indication of an affected compressor clutch is loss of power. A damaged clutch compressor fails to provide the necessary power to the AC system.
If the compressor clutch is damaged, you may also observe whining and grinding noises. Either way, there will be weak air flow from the AC or the cooling system might not blow cold air at all. It is necessary to be aware of the signs of a weak AC compressor in order to avoid any delays in repairs.
HOW TO FIX
For a damaged compressor, there are a few steps you can follow to overcome the problem:
- Check the compressor’s wiring to ensure all connections are intact. Clean and reconnect the connections. Additionally, look for any signs of corrosion and remove it.
- Examine the clutch compressor for any signs of wear. It might need to be replaced if the wear is excessive.
- Check the clutch plate for damage. If the damage is severe, it would need to be replaced too.
- Check the compressor clutch and clean it with a clean cloth or bruh. Be sure to get rid of all debris.
FAULTY EXPANSION VALVE
A damaged or faulty expansion valve can also be the reason why car ac only works when driving. Common symptoms of a faulty expansion valve include ineffective cooling or irregular noises coming from the air conditioning system.
Additionally, the car’s AC system might not work at all or blow warm air.
HOW TO FIX
A faulty expansion valve can be fixed by following these steps:
- Check the unit’s power supply. If the supply is turned off, switch it back on and see if the expansion valve starts.
- If the expansion valve doesn’t start, it needs to be replaced.
- To replace the expansion valve, turn off the power and remove the valve from the unit. Connect the new expansion valve to the unit.
- Turn the power back on and the valve shall work. If it doesn’t, you may need to take your car to a professional.
These were the major cause of why car ac only works when driving. An air conditioner is more of a necessity for places with humid temperatures. It adds comfort to a ride and driving in hot weather without an AC can be stressful.
Some common problems like AC blowing warm air or ineffective cooling can be fixed at home. However, if you’re unfamiliar with these processes, it is advised to take your vehicle to a service centre.
Luckily, the UAE has several AC repair shops ready to cater to all related needs. Check out the following:
If your car encounters frequent AC issues, it is a viable option to go for a pre-owned modern car. Browse through these used cars for sale in the UAE and have your pick.
Stay tuned to dubizzle’s auto blog for car air conditioning-related problems, solutions and more.
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