The sudden failure of your vehicle’s air conditioner can make your day miserable. Leaks and compressor problems are the most common reasons for a broken air conditioner. The problem may be a clogged air filter, a cooling fan issue, radiator problems, or simply that your AC needs to be recharged.
It’s unnecessary to put up with a stuffed-up, uncomfortable vehicle, nor must you depend on the mechanic to fix it. Knowing where to begin is the hardest part of figuring out how to improve your car. This guide will help you diagnose the problem with your climate control before taking it to a mechanic. Learn how to repair your AC yourself and save money.
Is your AC cool but not cold?
When the air conditioner is set on max cool with fans at high but only blows moderately cool air, it is:
When the air-conditioning system is running, check to ensure the cooling fan on the condenser or radiator is working.
Check for obstructions such as leaves, bugs, or dirt which could prevent air from flowing over the condenser.
To ensure it’s not blocked, check the air filter in your cabin.
The next step would be to check the pressures using a manifold set. You can find the recommended high-side- and low-side forces in your vehicle’s repair manual or online. After you’ve connected your gauges, it’s time to examine the AC compressor.
Start with the AC Compressor
It’s best to start with the compressor when diagnosing an AC problem.
While the engine is running, turn on the A/C to max cool and set the fans high. Also, make sure the clutch on the compressor is engaged. This is not the actual pulley but the center part that connects the pulley and compressor shaft. This indicates low refrigerant if the clutch engages and disengages every few seconds. The gauge will drop quickly when the clutch engages and reaches a low-pressure point. Then, the clutch will clear, and the pressure will increase. The meter should remain steady as you add refrigerant. With the compressor running, it should also hold the pressure recommended.
Use a Voltmeter to determine if the voltage reaches the compressor if the clutch does not engage and the system contains refrigerant.
If you have voltage, the clutch could be harmful.
There may be no voltage, a faulty cycling button, or a fuse is blown. The system might not have enough pressure from the refrigerant to trip the Low-Pressure Cutoff Switch, which cycles the compressor.
Leaks cause most problems
The most common issue with air conditioning systems is leaks. Leaks can occur when the pressure is too low.
The easiest way to detect a leak is by using an A/C Leak Detection Kit. Use the instructions provided on the package to add UV dye to the system. Then, use UV light to locate the leak.
Verify that all fixtures are secure.
Check the hose manifolds of your compressor.
On some compressors, check the front seal and the o rings that seal the pressure switches at the back.
Check the location of the hoses on the fittings.
Check for pinholes in the condenser.
Use UV light to check where the evaporator drains condensate. Occasionally, oil or dye may be visible.
Note that the dye test will not work when the system is low, or the compressor isn’t cycling.
The Accumulator/Drier is a device that collects and absorbs water. Moisture can poison internal system components and even damage the AC Compressor. You may have an accumulator or a receiver/drier depending on the vehicle.
Common Problems Internal failure that allows desiccant materials to enter the AC System. This stuff can be a problem if placed in a different place. Compressors can damage the desiccant if the material becomes oversaturated due to leaks.
AC ORIFICE TUBE / AN EXPANSION VALVE
The AC orifice tubes/expansion devices filter and regulate the coolant flow through your air conditioner system. You may have an orifice valve or an expansion tube depending on the vehicle.
Common problems: Contamination causes the majority of failures. The expansion device may be at fault if the system pressures have been set too high or too low. First, ensure the refrigerant is correct, and the radiator/A/C condenser fan (or fans) is functioning correctly. Always inspect and test your unit before replacing it!
The AC condenser is similar to a radiator and works with the fans. The air flowing over the AC condenser tubes is used to cool down the hot gaseous refrigerant, which has absorbed heat inside the vehicle. The refrigerant is then returned to its liquid state, where it can enter the evaporator and drink even more heat.
Common problems: Leaks of refrigerant. Poor cooling can be caused by contaminated particles in the AC Accumulator/Drier or AC Compressor. When checking the AC Condenser motors, check the radiator / AC cooling fans.
AC EVAPORATOR CORE
The AC evaporator is like a giant ice cube that has holes. The AC evaporator allows hot cabin air to pass through its core. It then cools the air quickly and blows the cooled air back into the cabin. The AC heater blower assembly is responsible for the cool air you feel coming from the dash vents.
Common Problems A leak caused by age and wear is the first reason for failure. The best way to detect leaks is with an electronic leak detector. Pay attention to the AC box evaporator water drain tube. You can use the tester to find a leak. A greenish-oily substance can appear in the drain tube if there are more significant leaks.
The advice, how-to guides, and car-care information on AutoZone.com, AutoZone Advice, and How-To are intended to be helpful resources only for general automotive maintenance and repairs. They should not be used as a substitute for professional assistance. AutoZone has done its best to ensure that the information is accurate. However, there could be errors, omissions, or mistakes.
Consult your owner’s guide, a Repair Guide, an auto zoner in a nearby store, or a professionally licensed mechanic for information on vehicle-specific repairs. Consult the service manual for details about your vehicle’s diagnostic, repair, and tool needs. Before lifting the car, always chock its wheels. Always disconnect the negative battery cables before servicing any electrical applications to protect the vehicle’s electrical circuits from accidental piercing or grounding. When working with automobile batteries, use caution. Sulfuric acids are acidic and can cause skin and clothing to burn. They can also cause blindness. Wear gloves, safety glasses, and any other protective equipment. Work in a well-ventilated area. If electrolyte gets on your skin or clothing, immediately neutralize the substance using a baking soda-water solution. Wear ties and loose clothing while working on your car.