AC no longer works correctly

My AC will no longer turn on unless you are pressing very hard and continuously on a specific spot near the AC dial.My mechanic said it might be an HVAC problem or something electrical. Before this, the AC would work, but only on Max AC.
Experienced mechanics share their insights in answering this question :
Sounds like you are having a problem with the a/c control unit. On some vehicles the switches are separate, but on most it is a complete unit and must be replaced as such. The unit can develop internal connection issues causing it not to run the a/c. Problems like these are not typical but they do occur. A certified mechanic will help pinpoint the problem with your a/c. Checking the unit and the wiring is important to make sure the unit is in fact the faulty part.

How to Identify and Fix Common car Problems ?

Our sources include academic articles, blog posts, and personal essays from experienced mechanics :

Reasons a Dodge Stratus AC Isn`t Working. The most common reasons a Dodge Stratus ac isn`t working are a refrigerant leak, an electrical climate control issue, or a problem with the air conditioning compressor. You may not realize there`s a refrigerant leak until the air conditioner stops blowing cold.
Dirty air filters are usually the most common problem that air conditioners face. Faulty motors are another common issue that air conditioners face and that can impact the cooling system. If the AC stops cooling suddenly, the thermostat should be checked.
Your car`s air-conditioning stopped working most likely because of a freon leak or a bad compressor. While these causes may be the simple to spot reasons that your air-conditioning isn`t cooling in your vehicle, a dirty cabin filter or a bad belt could also be the problem.
AC Works Intermittently: When the air goes from cool to warm to cool again, you`re experiencing intermittent problems. This is often due to a clog in the system, a failed compressor or compressor clutch, a faulty condenser fan, a clog in the system, or the actuator directing airflow has failed.
Dodge Ram climate control reset instructions

Step 1: Turn your fan to the lowest possible setting. Step 2: Hold down the climate control/conditioning button for 10 seconds. Step 3: Let go of the button, then press and hold it again until the lights on the button start flashing. And that`s it!

You might be low on refrigerant or have a worn out motor or a dirty evaporator coil. Not all AC problems demonstrate themselves with loud sounds or funny odors coming from your system. Some of them simply reduce the AC`s ability to run, and all you notice is less cool air in the house.
The most common causes of broken air conditioning leaks or compression issues. If you are feeling cool — but not cold — air, the issue could be a clogged filter, a problem with the cooling fan, signs of radiator trouble, or it could simply mean it`s time to recharge your AC.
Check to see that the cooling fans on the condenser or radiator are running when the air –conditioning is on. Look for any restrictions like leaves, bugs or dirt that would keep air from passing over the condenser. Check the cabin air filter to ensure that it is not clogged.
Your car`s AC stopped working most likely because of a freon leak or a bad compressor. Though these causes are the simple to spot reasons for your AC not working inside your car, it might be anything as simple as a dirty cabin filter or a bad belt.
Look for it first around on the exterior of your machine, especially along the bottom edge near the ground. An AC`s reset button is typically red and visible, so it should be easy to spot. If you don`t see a reset button on the outside, it could be located inside the unit behind the service panel.
Your air conditioner`s internal circuitry needs some time to reset after you turn it back on. This can take approximately a half-hour, so sit tight for about 30 minutes. Turn your air conditioner back on at the thermostat. After 30 minutes have passed, turn your air conditioner back on at the thermostat.
After turning off the circuit breaker linked to the AC unit, wait for a full minute. Set a timer for 60 seconds and then return power to the AC unit. As a safety precaution, it may be a good idea to inform everyone in your household that you will be resetting breakers.
Here`s the thing: It`s normal for your AC to run continuously during hot summer months. You see, on extremely hot days—we`re talkin` high 90s to 100s—your system needs to keep up with the incoming heat. To do that, it will run longer in order to maintain a constant, desired temperature in your home.
Air leaks and poor insulation are a common cause for making your house feel hot, even when the AC is working, as they can allow the air your air conditioner has worked so hard to cool to escape, leaving your house hot. Humidity can interfere with your thermostat`s ability to track temperatures and also traps heat.
A car A/C blowing hot air is often the result of a refrigerant leak. Refrigerant is a liquid that circulates through your car`s A/C system, expanding and contracting as it removes heat and humidity from the cabin. None of the other A/C components will function correctly without proper refrigerant levels.
When an air conditioning stops blowing cold air, it`s typically because the thermostat is set incorrectly or was altered. Children often play with thermostats they can reach. If this is the case, simply reset your device.
Generally speaking, when cool air blows during early morning hours, and then blows warmer as it gets warmer outside, it can be due to a few possible sources. First, and most common is that the AC vent is set to draw air from the outside and not through the cabin.
This can be caused by an electrical fault in the A/C compressor circuit or the magnetic clutch that drives the compressor. Another cause could be an internal obstruction inside the refrigerant circuit that is preventing refrigerant from circulating inside the A/C system.
If, on inspection, you hear chattering, whining, squealing, chirping, or rattling sounds coming from the AC compressor, it is time for AC service.
A car`s air conditioning should be recharged every two years or so. However, if you notice any signs that your AC needs to be recharged, it`s important to take your car in as soon as possible. Taking care of your car`s AC is important for several reasons.
The short answer is yes, coolant can affect air conditioning performance in a number of ways. Typically, coolant can affect your AC`s temperature, humidity, and airflow. Your AC`s temperature may be affected by the proximity of your car`s interior to your engine.
Some air conditioning systems have a reset switch, which is a small, red button. Typically, the button will be on the outdoor unit. If you have a problem locating it on the outdoor unit, you may find relevant details on the equipment`s manufacturer`s manual. Press the red button for three seconds and release.
The HVAC control board is where the thermostat wires connect to your heating and cooling system. In most cases the control board can be found at your furnace or air handler.
The method to reset your thermostat will vary depending on the model. Common methods for resetting a thermostat include installing the battery backward for five seconds, pushing a recessed reset button with a pin or paper clip, or shutting off the breaker to the thermostat for 30 seconds.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

Honda Civic 2008. AC stopped working suddenly and engine check light came ON for a day.Next day AC worked and no engine light.
ANSWER : Hi there. In both cases, when an AC system is not working and a warning light is coming on the dashboard, typically a professional mechanic will complete the same initial inspection, which is to download the stored error codes that triggered the warning light initially. This tends to give them an idea as to what is causing the problems. This could be something as simple as an electrical relay that is faulty or loose or an indication of a computer related "glitch". Either way, the best way to move forward is to have a professional mobile mechanic complete a check engine light inspection.

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My AC does not always work. If I fiddle with the blower knob I can ususally get it to work on the lowest setting.
ANSWER : Hi There,
It sounds like you may have a faulty blower motor resistor. The highest speed setting may still work because in most cars in the highest fan speed settings the current bypasses the blower motor resistor. In some cars, if the resistor is failed, the fan may stop working completely. Another reason a blower motor resistor may fail is when the blower motor has a mechanical problem or when a foreign object jams the blower motor fan blade and prevents it from spinning freely. This leads to increased current through the resistor and causes it to overheat and fail. I would suggest having an expert from YourMechanic come to your location to diagnose your system to determine what may be causing the fan not to work properly.

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My AC is not working took it the mechanic and he told me that’s it has a blown fuse box which is causing my AC not to work?
ANSWER : Hi there. I have not seen a fuse box fail very often on this vehicle. It is possible that he meant to say that the fuse for the AC is blown which makes a lot more sense. Most of the time when the AC fuse blows it is because the compressor is failing and has a short in the clutch.

The circuit is going to have to be tested for a short to confirm why the fuse blew. It can take some time to trace the wires, though it is probably the compressor. If you need to have this diagnosed, consider YourMechanic, as a certified mechanic can come to your home or office to inspect your AC system.

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My dash board don’t work my front light work when I change my light into high beam and my back window won’t go down
ANSWER : As unfortunate as it is, your vehicle would be considered flood damaged. Diagnosing electrical problems in a flood damaged vehicle is nearly impossible. This would take many hours or even days to determine which wiring harnesses and circuits have been affected. Then nearly all of the wiring under the dash would likely require replacement as well as many sensors and switches. On a BMW vehicle, the amount of wires and switches are likely more than that of a lower end vehicle. Due to the inefficiency in cost, you would likely be able to purchase another BMW like yours for less than what it would cost to fix your car. Many insurance companies would consider this type of damage to total out the vehicle unfortuantely.

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2003 honda odyssey cooling fans don’t turn on with AC, ac works while driving and shuts off when sitting still
ANSWER : If the fans are not working properly and consistently to cool and condense the refrigerant in the condenser, pressure in the system could rise high enough to trip the high pressure cut off switch, thus accounting for the compressor shut down. There is a control circuit for the fans and that circuit will simply have to be traced for BOTH voltage drops and continuity and, as well, proper function of the relays and any temperature sensors that might be in the circuit. The factory wiring diagram is essential. To obtain this diagnostic, and get the required repairs implemented, please request an a/c condenser control circuit inspection and diagnostic and the responding certified mechanic will get this resolved for you promptly. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

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AC wont blow on max
ANSWER : Based on the information you provided for your 2010 Dodge Avenger. It is likely that you have a leak in the air conditioning system. You may also have a resistor pack going bad, or the selector switch itself could be going bad. To have the problem verified, a certified technician from YourMechanic can come to your home or office to detect any leaks and make needed repairs.

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My ac slowly stopped working after just two days.
ANSWER : The air conditioning system relies on a full system charge to function properly. A poorly operating air conditioning system is usually caused by a low charge from a leak. If the air conditioning compressor electronic clutch fails, the fuse blows or the relay burns out, you will notice the lack of cooling. The refrigerant inside the air conditioning system is a gas whose use and handling require a certification. Consider hiring an experienced technician like one from YourMechanic who can come out and give your vehicles air conditioning system a performance check which includes checking system pressures in an effort to offer you a more personal diagnosis.

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Windshield wipers stopped working. They’ll suddenly stop working then suddenly start working again. Has been happening for a week.
ANSWER : The problem you are describing likely stems from an intermittent electrical fault in the wiper circuit. The windshield wiper system uses a small electric motor to move the wiper arms that you see on the windshield. That electric motor is controlled through a switch, relay, fuse, and wiring. One, or more, of those electrical components has failed although it is also possible that the mechanical arms are binding (seized, if the lubricant has dried out) thus causing the electric circuit to the motor to overload. Regardless of the underlying fault, if you request a non functioning wiper diagnostic/repair, the responding certified mechanic will get this taken care of for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

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