Free Car Diagnostic

Search for Free Car Diagnostic

Showing posts with label Car airconditioning. Show all posts
Showing posts with label Car airconditioning. Show all posts
Textual description of firstImageUrl

Mildew Smell in Car AC

If ac blows air that has a mildew odor, the problem could be the drain pan of AC's evaporator unit is not draining and causes mildew smell in car AC.

Mildew Smell in Car AC

Possible cause of mildew smell in the car AC

(1) AC evaporator unit is not draining.

First, we will need a little background information in order to understand what's going on here... A key component of an A/C system is the evaporator. While the A/C is on, the evaporator gets very cold. Air is then blown through the evaporator's many fins, thus causing the air coming out the A/C vents to be cold. On hot and humid days, condensation forms on the evaporator (since it's cold). This condensation/moisture drips down to the drain pan of the evaporator unit. Normally, this condensation is funneled down a hose and onto the street. Now, back to the problem at hand... air conditioner smells musty.

Mildew Smell in Car AC

If the drain pan isn't draining (due to a clog somewhere), moisture will get trapped in it (i.e. the drain pan). Such moisture breeds the growth of algae-like organisms, which tend to give off a mildew odor. This odor works its way up to the evaporator and is then blown out the vents (which is when you smell it-car ac smells musty).

What to do?
Crawl under the car and locate the hose which leads up to the evaporator drain pan. Refer to a manual covering your car model if you need help in finding it. Once you locate the drain hose, clean any mud or debris from its end. However, if the end of the hose isn't clogged with mud/debris, the clog must either be further up the hose or else in the base of the drain pan. In this case, you'll probably need the assistance of a professional in order to locate and clean the clog/blockage.

How to Unclog Your Car AC Drain Line



Once the drain pan is again draining properly, it will take at least a couple of days for the algae-like organisms to dry up and thus the mildew smell in car AC to go away.

Car Not Blowing Air

When the car ac is not blowing air from vents in the car it is a sign of a faulty blower fan or air duct blockage. A faulty blower fan can make the car ac stopped working suddenly.

Learn more: Car Not Blowing Air

Textual description of firstImageUrl

Car AC Not Cold Anymore

Car AC Not Cold Anymore

If the car AC is not blowing cold air anymore over time it is an indication of a slow refrigerant leak or a clogged condenser.

Possible cause why car ac is not cold anymore

Textual description of firstImageUrl

My Car AC is Blowing Hot Air

 Car AC is Blowing Hot Air

The car Ac is blowing hot air suddenly or is blowing hot air slowly over a period of time. When turning the AC switch ON usually, cold air is coming out of the AC vents. But when the AC switch is turned ON instead of cold air, hot air is coming out the vents.

Possible cause why car ac is blowing hot air

Major Refrigerant Leak



If initially when turning the ac switch the ac vents is blowing cold air, then suddenly the vents are blowing hot air, it is an indication of a major refrigerant leak. The refrigerant is a liquid inside the ac system. The liquid takes away heat from the passenger compartment and purges it outside thereby creating a cooler environment from inside the passenger compartment. When there is a major refrigerant leak somewhere in the system because of ruptured hoses, the refrigerant will evaporate and the ac system will reduce its performance. Since the refrigerant evaporates, the ac vents will be blowing hot air instead of cold air.

Open the hood of your car and check the ac line for any ruptured hoses. Replace the ruptured hose.

AC Electrical Problem

The electrical system possibly the switches or wire is shorted or the fuse of the ac unit break which causes the ac system to malfunction. Check the fuses if busted. If the fuses are busted then this is what causes the problem.

Even though the fuse is replaced, it is most likely to be busted again because the cause of why the fuse is busted is not yet identified and repair. Therefore bring the car to a reputable shop and have the ac electrical system examine by a qualified mechanic.

Small Leak on the AC system

If the ac blows cold air then slowly blowing hot air over a period of time, it only means that there is a small leak somewhere on the ac system. A small leak on the system tends to drain out the refrigerant slowly over a period of time and slowly reduces the ac performance.

Car AC Not Cold Anymore
If the car AC is not blowing cold air anymore over time it is an indication of a slow refrigerant leak or a clogged condenser.
Read more: Car AC Not Cold Anymore

Bring the car to a reputable shop that specializes in car air conditioning system. Ask the mechanic to check for any leak on the system and have it repaired.

Clogged Condenser

The condenser is one of the components of the car ac system that serves as a mini radiator that removes the heat that the refrigerant absorbed in the passenger compartment. Over time the condenser will be clogged because of dirt or debris coming from the outside surroundings and it can slowly make the car AC to reduce performance which is why the car ac is blowing hot air.


Check the condenser for the buildup of dirt and clean using a soft brush and water. It should improve the performance of the ac system. If not then bring the car to a car shop that specializes in the car air conditioning system. Ask the mechanic to examine the ac hoses for any leak on the system, also for the electrical system for any short circuit. Recharge the system with new refrigerant after the repair is done.

Car AC not Blowing Air from Vents

When the car ac is not blowing air from vents in the car it is a sign of a faulty blower fan or air duct blockage. A faulty blower fan can make the car ac stopped working suddenly.

Learn more: Car AC not Blowing Air from Vents

Mildew Odor Comes Out the AC Vents

The air that comes out the air conditioning vents has mildew odor. The reason for this problem is that the drain pan is not draining.

 

Textual description of firstImageUrl

1998 Blazer AC is Blowing Hot Air

We received a lot of email queries about a 1998 blazer hot air blowing air conditioning system, so instead of answering the email one by one, we decided to discuss the problem.


Troubleshooting 1998 blazer hot air blowing AC

If the problem suddenly occurs this indicates a major refrigerant leak. The refrigerant for car air conditioning is a major component of the system that serves as the lifeblood of the system. It is the one that carries heat coming from the passenger compartment and dump the heat outside the car to make the passenger compartment cooler.

When there is a rapid leak anywhere in the system the air conditioning performance will reduce and start to blow hot air instead of cool air. Also, it is possible that the wires of the ac system are shorted causing the fuse to pop out. Another possible cause but not commonly occur is the problem on compressor, usually a broken or slipping belt that drives the compressor is the problem or the compressor clutch is not engaging.

Cause of the problem:
The major refrigerant leak, shorted wire or ac switch, broken or slipping compressor belt, compressor clutch not engaging.

Check first the ac system, open the hood and observed if there is a broken or ruptured ac hose. Then check the compressor belt if it is broken or slipping, when the belt is slipping a sound can be heard. When everything looks fine the next thing to check is the circuit breaker, you may find the circuit breaker by referring to the vehicle owner’s manual. Reset the breaker to fix the problem, but it may pop out again so it is better to bring the car to a shop specializing in the air conditioning system and ask the expert to check the electrical system then repair if necessary.

Car Not Blowing Air

When the car ac is not blowing air from vents in the car it is a sign of a faulty blower fan or air duct blockage. A faulty blower fan can make the car ac stopped working suddenly.

Learn more: Car Not Blowing Air
Textual description of firstImageUrl

Diagnose and Repair Car Air conditioning System

Principles of air cooling of the AC system
The principle that is applied to the automotive air conditioning system is that when a liquid turns into vapor it will absorb heat so that the surrounding area cools down. It is similar to the principle that when a body is wet and the perspiration is exposed to the wind the body will feel cool.

Refrigerant flow
The illustration shows the basic structure of the air conditioning system of an automobile. The cycle is that the refrigerant changes state from the liquid state to the vapor state and back to the liquid state again. The liquid becomes gas when the refrigerant absorbed heat and the surrounding becomes cool, then the gas is compressed making the refrigerant temperature to rise, now as the gas cools down it will return to the liquid state.

Components of Car A/C
Compressor
This component is the one responsible for increasing the pressure and temperature of the refrigerant once the refrigerant evaporates. The compressor serves as the heart of the system.

Condenser

The condenser keeps the refrigerant to its liquid state.



Receiver dryer
The receiver dryer is responsible for expanding the refrigerant so that the temperature will go down.



Expansion Valve
The expansion valve is the one that cools down the refrigerant from high temperature and pressure so that the refrigerant will return to the liquid state.


Evaporator
This is where the refrigerant changes state from liquid to gas, as the refrigerant changes state it will absorb heat.

Usage of tools and equipment
1. Moisture and air still exist on the refrigerant line, therefore, evacuation of the system is necessary to be done so that the moisture and air will be removed.

2. In connecting the manifold gauge on the A/C system, the blue hose must be connected to the low-pressure side and the red hose is connected to the high-pressure side. The yellow hose is connected to the vacuum pump or charge valve. The manifold gauge can be used for R12 and R134 air conditioning system.

3.Used a service valve so that the amount of refrigerant that is discharged to the air is minimal.

4. Weight the amount of refrigerant to charge to the a/c system depending on the car model.

5. Connect the A/C refrigerant pipes and use a torque wrench to tighten the nuts.

Change of pressure and temperature
When there are changes in the pressure and temperature of the refrigerant system it means that there is a malfunction on the system.

Trouble diagnosis for an unusual pressure
When there is an unusual pressure on the high and low side of the system use a manifold gauge to diagnose the problem. There is a marker above the manifold gauge scale that indicates the standard pressure corresponding to the standard pressure range.

Hi and low side pressure is very high using the manifold gauge
1. The pressure is reduced after water is splash on the condenser, this means that there is an excess of refrigerant charge on the system. To correct the problem just reduce the amount of refrigerant on the system until the correct pressure is attained.

2. Air suction by cooling fan is insufficient, the possible cause is that the condenser fins are clogged or the cooling fan rotation is improper. To fix this problem try to clean the condenser or check the cooling fan and repair if necessary.

3. The low-pressure pipe is not cold or when the compressor is stopped the high-pressure value quickly drops at approximately 196 kpa and then gradually decreases thereafter, this means that there is a poor heat exchange in the condenser because of air in the refrigeration cycle. To fix the problem evacuate the system repeatedly and then recharge.

4. The area of the low-pressure pipe is colder than the area near the evaporator outlet or the plates are sometimes covered with frost, this means that there is an excessive liquid refrigerant on the low-pressure side or an excessive refrigerant discharge flow or the expansion valve is opening is small compared to the standard. Usually, the cause of the problem is the improper installation of the expansion valve or improper adjustments of the expansion valve. To fix the problem, the expansion valve should be replaced.

The high-pressure side is too high and low-pressure side is to low
1. The upper side of the condenser, as well as the high-pressure side, are hot but the liquid tank is not hot, this means that the high-pressure tube or parts located between the compressor and the condenser are clogged or crushed. To fix the problem check for the contamination of the lubricants, also check and repair the malfunction part.

High-pressure Side is Too Low and Low-pressure Side is Too High
1. After the operation of the compressor stops the high pressure and low-pressure side becomes equal, this means that the compressor operation is improper because of damage inside the compressor packings. Just replace the compressor to fix the problem.

Both the high and low-pressure side is too low
1. The outlet temperature is extremely low and there is a big difference in the outlet and inlet of the receiver drier. The liquid tank inlet and expansion valve is frost. This means that the liquid tank inside is slightly clogged. To fix the problem just replace the liquid tank and check the lubricant for contamination.

2. The expansion valve inlet temperature is lower than the temperature near the liquid tank. The expansion valve inlet may be frosted. There is a temperature difference between the high-pressure side. This means that there is clogged on the pipe between the receiver drier and the expansion valve. To fix the problem check the system for lubricant contamination, also check and repair the malfunction parts.

Low-pressure side sometimes become negative
1. The AC system does not cool the compartment air. This means that the refrigerant does not discharge or the moisture is frozen on the outlet and inlet of the expansion valve. Also, there is water that is mixed with the refrigerant. To fix the problem, drain the water from the refrigerant or replace the refrigerant. Also, replace the liquid tank.

Car AC not Blowing Air from Vents

When the car ac is not blowing air from vents in the car it is a sign of a faulty blower fan or air duct blockage. A faulty blower fan can make the car ac stopped working suddenly.

Learn more: Car AC not Blowing Air from Vents
Textual description of firstImageUrl

Car AC Blows Air with Mildew Odor

When the car air conditioning is turned on, the air that comes out the air-con vents is with mildew odor.


Reason why car ac blows air with mildew odor

Drain pan of AC unit is not draining


Car troubleshooting

Car air conditioning has a component called the evaporator, when the air conditioning is turned on the evaporator gets very cold then if the air is blown through the evaporator the air will turn out to be cold after it passes the many fins of the evaporator and going out the air conditioning vents. Now, during hot and humid days a condensation is formed on the evaporator because the evaporator is cold. The moisture that is formed will drip down into the drain pan of the evaporator unit and then it is funneled down a hose going out the road.

When it is clogged somewhere in the system the drain pan will not drain and the moisture will get trapped in the drain pan. The trapped moisture will encourage the growth of an algae-like organism that will create a mildew odor which can be transmitted all the way up to the evaporator.
If the mildew odor reaches the evaporator the smell will then be carried by air going out the air conditioning vents.

How to fix the mildew odor coming out the car air conditioning vents

The first thing to do is to locate the hose that is connected all the way to the evaporator drain pan. If you cannot locate the hose you may refer to the manual that covers this car for reference on the location. If you located the hose, check the end of the hose if there is debris or mud and clean if necessary. If the end of the hose is not clogged then check the base of the drain pan it might be in this portion where the clogged is presence again clean the hose if necessary. Once the clogged on the system is cleaned the drain pan will drain properly. But the mildew odor will not yet be removed it will take a couple of days the mildew odor will completely remove.

Car AC not Blowing Air from Vents

When the car ac is not blowing air from vents in the car it is a sign of a faulty blower fan or air duct blockage. A faulty blower fan can make the car ac stopped working suddenly.

Learn more: Car AC not Blowing Air from Vents

Do it yourself

Step by step do it yourself easy to understand basic car maintenance for the car owners.

How to Install a Car Battery

While engine is running, use the meter to check the alternator and voltage regulator output. This is very important because a faulty alternator or voltage regulator can cause a premature battery failure and you do not want this to happen.

How to Check Tyre Pressure

The tyre thread life could reduce if the tyre pressure of your car is under what the car manufacturer specified on your car owner’s manual.

How to Change a Flat Tire

When you encounter a flat tire while you drive your car the first thing to do is to pull off the road away the traffic as possible.

How to Recharge a Car Battery

Before attempting to recharge car battery always make sure that the battery is at room temperature (60 °F to 80°F). Also, when it is extremely cold remove the battery from the car and bring it indoors to allow the battery to become warm before begin the charging.

How to Disconnect a Car Battery

Do you know how to disconnect a car battery? Suppose you want to clean or replace the battery and needed to disconnect the battery to make the job well then here is what to do.

How to Replace Windshield Wipers

When you have a car it is important that you have knowledge with basic car maintenance like this simple step on how to replace windshield wipers.

How to Jump Start a Car Battery

Jump a starting car is easy but should be done correctly so that accident such as a battery explosion can be avoided that may result to the damage of your car or worst injured you. Here's how to jump start a car.

Popular Car Diagnostic Post

Visitors