Being trapped in traffic in a hot car during summer can ruin a perfect summer day. It also increases your chances of getting a heat stroke, especially if you will be in your vehicle for a prolonged period, which is why getting your Car AC in tip-top shape before summer is a necessity.
This guide seeks to help you use your car AC more efficiently and learn how to fix minor issues that may cause the AC not to work correctly.
Why is my car heater blowing cold air?
Your car AC should not be blowing cold air instead of warm air, especially on chilly mornings and nights. And if it happens to be on cold winter nights, then you are in deep trouble. Several issues can cause the cold air blowing instead of warm air;
Not Enough Coolant
When your car is low on coolant, it won’t send any to the heater core to create warm air. This is because the coolant is responsible for transmitting warm air from the engine to the heater core.
Problems with Heater Core
A malfunctioning heater core can prevent the heater from blowing warm air. It is essentially a car radiator made up of brass or aluminum tubing that carries the hot coolant in and out of the car heater.
Signs of a faulty heater core include;
- Fog inside of your car
- A fruity, sweet-smelling odor
- Your car using coolant very quickly
- The engine overheating
Broken or Clogged Heater Controls
Damaged heater controls can prevent transmission of the heat regulation signal. If the buttons are stuck, the heater will not be able to turn on the heating core to blow hot air. Clean them if they are gummed up or replace them if necessary.
Dysfunctional Thermostat
If you notice that your thermostat gauge stays on the “C” even after the engine has time to heat up, you may have a broken thermostat. If the thermostat can’t signal to the car that the engine is warm, the coolant won’t be sent over to provide heat to your heater core, and the air will stay cool. Thermostats are a relatively easy and inexpensive fix, so installing a new one can get your heater working again quickly.
Water Leaks
Water leaks can prevent the transmission of heat to the heater. Inspect your car’s hoses, radiator, and water pump for damage and ensure they do not leak.
Note: ensure you get the issues fixed properly to ensure the heater does not break down during winter.
Why is my car AC blowing hot air?
Hot air circulation during a hot summer day can be just as uncomfortable as cold air circulation during winter. And if you live in a dry area, the probability of severe heat waves side effects can be highly hazardous.
Here are some causes of hot air emission instead of cold air;
Your Car is Leaking Refrigerant
Leaking refrigerant mainly occurs in the AC’s hose connections. This may cause the AC to emit hot air as it cannot cool it down before blowing it out. Check to see if you see an oily substance leaking at the hose connection points. Then use an AC sealant to repair the connection points.
The Condenser is Blocked
The condenser re-cools hot refrigerant once it has been compressed. It uses the airflow that comes in through the front of your car as you drive. If the condenser is blocked, it will not be able to cool the refrigerant properly, which in turn will cause your car’s AC to continue circulating hot refrigerant.
The Condenser is Broken
A broken condenser cannot cool refrigerant properly, causing the AC to expel hot air. It can be caused by a puncture resulting from road debris going through the grill of your car and damaging the part. It can also be a result of wear and tear.
Electrical Issues
Broken or frayed wiring will prevent your AC from working correctly. Inspect your car and repair any damaged wiring or replace it if needed. You can also use a multimeter to check for continuity.
Faulty Cooling Fans
If the fans in the AC are faulty, the condenser will not be adequately cooled, causing the AC to expel hot air. Visually inspect the fans to see if they are damaged and repair or replace them as needed.
Damaged Compressor
If your compressor stays dormant for a long time, it may get damaged due to the stagnation of the refrigerant in the system. This may ultimately shock the system.
Why is the heat in my car not very hot?
The leading cause of low heat in your car’s AC is a malfunctioning heater core. This can be a result of a dirty AC system or more severe underlying issues. Here are the leading causes of low heat in a car AC;
Faulty Thermostat
Your car’s thermostat may cause the heater to produce less heat than anticipated if it cannot regulate the temperature properly. If this is the cause of the low heat, repair or replace the thermostat and see if the condition improves.
Low Antifreeze/Coolant
A low level of low antifreeze or coolant is another major cause of low heat emission. This is because they prevent proper heat transmission to the heater core, thus causing it to produce a low amount of heat.
Faulty Heater Fan
A broken heater can prevent the transfer of hot air. If the fan system is shorted, the fan will not blow heat through the car AC.
Faulty Blower Motor Resistor
If the blower motor resistor is broken, you might have issues setting the fan speed or getting air at all.
Clogged Heater Core
Rust from the radiator or lodges dirt may collect in the coolant system from time to time. This debris can clog the heater core, which may prevent it from heating up properly. You can either repair the heater core or replace it depending on how clogged it is and whether it functions correctly after the cleanup.
Leaky Radiator
Radiator leakage will reduce the amount of coolant being circulated, thus reducing the heat the heater core can emit.
Faulty HVAC Controls
Malfunctioning buttons or a malfunctioning touchscreen will also prevent your heater from working as it is not getting the correct instructions when you program it.
Faulty Wiring or Blown Fuses
Faulty wiring and damaged fuses can also prevent the heater from working as it is not getting the electric continuity needed to trigger commands and power the AC.
Can low coolant cause no heat?
Yes. When the coolant level is below the minimum level, the heater core will not work correctly, causing your heater not to produce any heat. It may also overheat when it is low, causing the coolant temperature sensor to send a false signal to the computer. Which in turn affects the fuel and timing calculations and causes poor engine performance and fuel economy.
Additionally, low coolant causes the engine to overheat, which may be detrimental to your car. Some engines have an automatic cut-off that shuts off the engine when it overheats. Refill the coolant when it gets below the MIN level on the reservoir. But wait for the engine to cool down as the coolant is scalding when the engine is hot.
Why is my car heater working intermittently?
The car’s AC works by circulating hot coolant through the heater core, and the heat blows the emitted heat from the heater core into the vehicle. Here are the leading causes of intermittent heat emission;
- Loose wire connection
- Dead spot in the blower motor.
- Bad switch in the dashboard
- Damaged control module
- Faulty fuse or circuit
Check this too: Why Is My Car’s Remote Start Not Working?
Why would my car overheat, but the heater blows cold air?
Engine overheating has nothing to do with cold air emission. This is because the compressor is responsible for cooling the car using power sourced from the engine. The causes of cold air are due to a malfunctioning heater core or other parts of the AC.
Here are the main reasons your heart is blowing cold air;
- Low coolant levels
- A plugged/clogged heater core
- A faulty thermostat (thermostat that is stuck)
- Broken blower and blower motor
- Heater core bypass hoses that have leaks
- Heater core bypass hoses that are worn
That said, car overheating is caused by problems in the engine’s cooling system. These include;
- Engine cooling system leaks
- Low levels of coolant
- A faulty thermostat (thermostat that is stuck in the closed position)
- A blockage in the coolant passageways
- A faulty radiator
- Worn out radiator hoses
- A faulty radiator fan
- A faulty water pump
How to use your car air conditioning efficiently?
Come summer, your car’s ac system will be the primary source of fuel consumption increase as you need to stay cool while driving in the hot summer heat. To ensure you do not mess up your vehicle’s fuel economy too much, you can use several methods to increase energy efficiency.
Here are several methods you can use for efficient AC usage;
Don’t leave the AC on
No matter how tempted you are to pre-cool your car, resist the urge. This can increase fuel consumption considerably while only offering a few extra minutes of immediate comfort. Waiting a few minutes for your AC to cool your car down cannot harm you and is energy efficient in the long run. Opening your windows immediately after you get in should offer immediate cooling.
Set the AC at a lower temperature
Setting your AC to the lowest temperature will cool the car efficiently without using a lot of fuel. Additionally, the lower temperature setting prevents air reheating which will burn more energy.
Avoid re-circulation
Turn off the re-circulation mode to prevent further fuel consumption as the AC is doing double the work when recirculating the hot air from the back.
Clean or replace your filters
Dirty filters prevent airflow, which results in more power consumption. Check the filter for dirt and clean it regularly. You should also replace the filters regularly. This also minimizes the amount of pollen and particles in the air circulated when you turn on the AC.
Park in the shade
This prevents your car from overheating, which minimizes the amount of time it takes to cool the vehicle. Opt for a covered parking spot or in basement parking to keep your car cool. If these options are not available, park near some tree or under the trees.
Also, cover your leather seats to prevent them from heating up to reduce heat buildup in the car.
Use Automatic Climate Control
If you have the automatic climate control feature, adjust the temperature setting as needed. This minimizes energy wastage due to cooling when not required. Program your preferred temperature setting and let it do the rest.
Leave your windows cracked.
Ventilate the car by leaving the car windows slightly open to minimize heat buildup. It also allows hot air to escape and lets in cold air. Also, close the windows once you turn on the AC to prevent loss of cooled air while you drive.
Replenish the refrigerant
Ensure your AC has enough refrigerant to enable the compressor to cool the air efficiently. The low coolant level will require your AC to work harder to cool the air.
Service the AC
Maintenance is essential for optimal performance. Here are the main areas to tackle when servicing your AC;
- Check the air vent temperature.
- Reclaim, recycle or replace the operating (refrigerant) gas
- Replace or check receiver drier / filter
- Adjust drive belts and pulleys
- Check operation of valves and thermostats
- Test system lines and components for leaks and damages
- Inspect various hoses and components
- Clean the condenser fins.
- Deodorize and sanitize the air conditioning system
Use your AC regularly.
Turn on your AC at least 10-15 minutes weekly to keep things moving in the system. This will prevent blockage as well as the stagnation of refrigerants.
Turn off the auto on/off AC feature.
This will save fuel by not keeping the AC running even when it is not needed.
Turn the AC off
Turn off the AC before you turn off the ignition. This will prevent energy consumption when the AC turns on when you turn on your car. Let your fan run after switching off the AC to ensure the evaporator is dried out. This will prevent the growth of bacteria, fungal spores, or moss in the AC, which can cause foul air emission or respiratory diseases.
Signs of a failing car AC compressor
A failing car AC in the middle of summer can be highly inconvenient, especially if you live in a high heat zone area. To avoid this scenario, it is vital to diagnose a failing AC compressor; before it fails. To be able to troubleshoot and fix your AC compressor, look out for these signs;
Odd Sounds
Your AC will produce strange noises when you turn it on your vehicle’s air conditioner. The sound can be grinding or whining sounds depending on the components of the compressor that are damaged. Turn on the AC severally to confirm if the powering action causes the sound. Suppose the sounds persist, repair or replace the compressor.
Hot Air
If your Ac compressor fails, it will blow out warm or hot air instead of cold air as it cannot cool the refrigerant responsible for hard air emission. Check to see if the Freon levels are low, and then fix the compressor if the low refrigerant is not the cause of the warm air.
Fluid Leaks
Worn-out bearings can cause leakage of refrigerant. This is a sure sign that the compressor has worn out or damaged parts that need to be replaced.
Stuck Clutch
The AC compressor has a clutch that connects to your vehicle’s engine to draw power from it. If the AC compressor clutch or its pulley gets stuck, the compressor will not work due to lack of power. When this happens, you have to replace the compressor as you cannot replace the clutch on its own.
Higher Temperatures than usual in the cabin
The first sign of a failing compressor is hot air emission instead of clod air. This is because the compressor is not able to cool the refrigerant as it should. Before replacing the compressor, ensure there is no refrigerant leak, and the level of Freon is above the minimum level.
Loud Noise When Compressor Is Running
A noisy AC is a sure sign of a failing compressor. This could be due to damaged internal components, failing inner bearings, or worn-out parts. While you may fix and replace some of the parts, in most cases, the best option is to replace the entire compressor.
Broken Suction Lines
Broken refrigerant lines will prevent the transmission of coolant to the compressor. You can remedy this by having a professional repair or replace the pipes.
Faulty wiring
Damaged wires prevent continuity of electrical current, making it impossible for the C to get the power it needs to work. Too much or too little voltage will also damage the compressor, which may require a replacement.
Why does my car vibrate when I turn the AC on while at a red light?
The AC compressor operates pretty much like a small engine and comes equipped with a motor. This tends to strain the engine, especially if the car is idling due to braking. The engine compensates for the drag caused by the compressor by triggering idle speed or the air control motor.
If this does not work, the extra drag will cause the car to vibrate due to the additional drag caused by the AC compressor as it draws power from an idling engine. That said, there can also be other reasons why the car vibrates. These include;
- Broken motor-mounts
- Excessively high AC compressor pressure
- Damaged transmission mount
Can an AC compressor cause check engine light?
Yes. A damaged AC compressor can cause your engine to seize up. If your car’s AC system turns on when it is not being used, it will use up extra power, leading to a misfire, which will cause the engine light to turn on, especially if your car has a high-voltage electric compressor.
How to tell if your AC is out of refrigerant (gas)
The refrigerant in your car is essential for circulating cooled air within the car’s AC. The coolant gets cooled in the compressor, and the AC’s fans blow the cold air out. However, if your AC does not have enough refrigerant, the system will not be able to blow out cold air. Here are some ways to tell you AC is out of refrigerant;
- The air being blown out is not cold enough
- The refrigerant is leaking from the AC’s connection points
- No sound when you turn on the AC due to lack of clutch engagement
Can low Freon cause check engine light?
Yes. When the car has a low Freon level, the PCM will detect a low signal from the low-pressure cut-off switch. This will, in turn, cause the Check Engine light to light up due to the registration of the Error Code P0534 in the vehicle’s memory system.