Is there any simple way to diagnose why my AC won’t blow cold?

It worked fine last summer. This summer I turned it on and it only blows hot air… so we got a can of refrigerant and was going to charge it but the Guage reads full. I don't hear the compressor coming on but when I had to have a new computer out in it the guys at the shop told me the ac compressor was good. Any ideas?

My car has 161165 miles.
My car has an automatic transmission.

Experienced mechanics share their insights in answering this question :
Hello. I will help you with this issue. If the a/c compressor is NOT running (and thus NOT creating suction in the refrigerant piping on the low side) and you apply a gauge to measure system pressure on the low side, the gauge will give a relatively high pressure reading (the reading will indeed appear as "full" in the DIY refill systems) even if the system is nearly empty. What you have to do is put a manifold gauge set on both the low and high sides of the A/C system.

If the compressor is not running, briefly force it to run by energizing the clutch. As the compressor kicks in, quickly read the pressures (don’t run it long because if system is low on refrigerant, that means the oil in the system is not circulating either and you will ruin the compressor by running it without adequate oil circulating). If the system is low in refrigerant, the low side might read as low as a vacuum on the gauge, and the high side pressure will be way too low (out of spec.), like maybe 80 or 100 PSI when it should be 180 to 250 PSI, depending on ambient temperature.

The best thing to do is have a Technician perform these diagnostic tests (refrigerant is dangerous; you will be blinded if liquid refrigerant sprays in your eye and if enough liquid refrigerant happens to spray on your skin you can be permanently injured). YourMechanic, being mobile, can come right to your door and take care of it. If the system is low, you might have a leak.

I say "might" because automotive systems are not like the nearly (or actually) hermetically sealed refrigeration systems that you are used to at home. Those systems are NOT supposed to leak at all during normal operation. Auto systems though generally "seep", due to the type of sealing technology (o-rings, etc.) that is used and the harsh operating environment and so although the amount that seeps is very small, over 12 years you WILL lose a certain amount of refrigerant.

If you are lucky, the reason it is low now (if it is low) is due to the normal loss that occurs over many years. If you are not lucky, you have a leak, the magnitude of which can vary quite a bit depending on where it is. In any event, anything is repairable and YourMechanic can both diagnose the current failure, identify any leaks that are significant and ultimately do whatever is necessary to get your A/C system functioning properly. Finally, your car uses a refrigerant that is designated as R134a.

How to Identify and Fix Common car Problems ?

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If the clutch doesn`t engage, the problem could be a blown fuse, an open in the wire to the clutch coil, a bad clutch coil, a poor ground, or a low pressure lockout. In some vehicles the compressor clutch relay is turned on and off by the low pressure switch and the evaporator temperature sensor.
With the AC off, the clutch does not spin. When you turn the AC on, the clutch can make a momentary click and starts spinning with the belt and pulley. If the clutch does not engage, or if it makes a screeching or whining sound when it does, the compressor needs to be serviced.
The most common reasons a Honda Accord 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.
If the compressor isn`t starting, check the wiring connecting the two units. If it`s a blown fuse or tripped circuit breaker, the search has come to an end. Other potential causes may include a faulty thermostat, mismatched indoor and outdoor units, or the AC may just be old.
Yes, you can technically replace the clutch without removing the compressor. The reason people suggest doing them together is that when one fails, the other usually isn`t too far behind it. It`s just a matter of convenience to replace them both since you`re already doing most of the same steps anyway.
You will be fine as long as you don`t need or want AC in your car. Your AC pulley is a free spinning pulley that has a clutch on it. It will spin freely until you turn the air conditioning on. If the clutch doesn`t work properly, you will still be able to drive your car.
To reset a malfunctioning Honda Accord climate control system, turn on accessory mode, then hold the defrost and OFF buttons on your climate control unit until the light has blinked five times.
A dirty air filter can block airflow and reduce cooling to your home. In more extreme cases it can cause the system to shut down completely. If your thermostat checks out and you still don`t have cool air, locate your system`s air filter, turn the system off, remove the filter and inspect.
When your ac compressor fails, less air will come out from the vents, the air coming out could be warm, and the system may continually run without actually cooling your home. This is because refrigerant isn`t pumped through the system, and it can result in a higher power bill.
Loss of refrigerant: This is the #1 way a compressor might die years before its time. The amount of refrigerant in an air conditioner is specially set to work with the compressor. If the AC loses refrigerant through leaks, the imbalance will eventually cause the compressor to overheat.
In some instances, AC compressors can be repaired. However, it is most often a better procedure to replace the faulty compressor with a new one. It is not only the most time-effective solution to the problem, but it will also most often result in a better, more durable repair.
Compressors and condensers are often replaced simultaneously, mostly because compressor failures can leave behind debris that the condenser collects. If this debris isn`t 100% removed, it will cause the new compressor to fail as well.
The good news is that yes, you can drive your car without an AC compressor. This is one of those “if you can`t stand the heat, get out of the kitchen” situations.
The job of the compressor is to pressurize the refrigerant, turning it from a gas into a liquid. The condenser`s role is to further cool down the refrigerant and exchange heat with the surroundings.
Most AC clutches are designed to spin freely when disengaged, and also with the pulley and compressor when those are engaged. If the clutch spins freely at all times, and the compressor never comes on, then it may not be engaging and therefore needs to be replaced.
If the compressor clutch doesn`t engage; that usually means, there`s an electrical or mechanical problem with the compressor. If the AC is not blowing cool air into the car, you may want to do a visual inspection of the AC compressor clutch and determine if you can see what might be causing the clutch to not engage.
A second reason for the air conditioning unit to suddenly prefer blowing warm air may be because the compressor itself has gone bad. The main function of the compressor is to pressurize the contents in the refrigerant, and then pump it throughout the necessary components of the AC.
Up to 1.5 million 2016-2021 Honda Civics in the U.S. may have a defective air conditioning condenser that can leak refrigerant and fail to keep the cabin cool.
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.
A reset button can be found inside the air conditioner`s compressor. Typically, the button is red in colour and modest in size.
Compressors generally last the lifetime of a car, or approximately 12 to 15+ years depending on how well the car is looked after. In saying that, it`s important that you regularly check up on and service your car to prevent premature failure. Some ways you can tell if something is failing can include: Leaks.
Another common point of failure on a Honda AC compressor are the seals that contain the oil that keeps the internal components of the compressor lubricated. And after tens of thousands of miles on the average Honda, it`s common for these seals to leak.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

Overheats When Blowing Warm With Heat & AC But Not When Blowing Cold AC
ANSWER : Hello, thank you for writing in. There are so many different codes being triggered, that it is unlikely all of these systems are having issues at once. We need to focus in on the fact the engine is overheating at all. You will want to check the level and condition of the coolant and the overflow tank. If the level is full then you may have an issue with the thermostat, radiator cap, or water pump. These can all be tested and changed relatively easily. If the main cooling system is okay, you will want to look into the heater core and climate control module. For more diagnostic help, contact our service department to schedule an appointment.

everytime I turn my car on the ac starts to blow air even if I switch it off. it won’t blow cold air or heat.
ANSWER : Hi there. Based on your question and input, it looks like your AC control switches are damaged, causing the vents to activate even if the switch is not activated. This is sometimes an electrical problem, as it could be triggered by a damaged electrical relay. You might want to have a professional mechanic complete an AC is not working inspection, so they can determine what is causing this issue you’re experiencing and recommend the right repair.

Is there any simple way to diagnose why my AC won’t blow cold?
ANSWER : Hello. I will help you with this issue. If the a/c compressor is NOT running (and thus NOT creating suction in the refrigerant piping on the low side) and you apply a gauge to measure system pressure on the low side, the gauge will give a relatively high pressure reading (the reading will indeed appear as "full" in the DIY refill systems) even if the system is nearly empty. What you have to do is put a manifold gauge set on both the low and high sides of the A/C system.

If the compressor is not running, briefly force it to run by energizing the clutch. As the compressor kicks in, quickly read the pressures (don’t run it long because if system is low on refrigerant, that means the oil in the system is not circulating either and you will ruin the compressor by running it without adequate oil circulating). If the system is low in refrigerant, the low side might read as low as a vacuum on the gauge, and the high side pressure will be way too low (out of spec.), like maybe 80 or 100 PSI when it should be 180 to 250 PSI, depending on ambient temperature.

The best thing to do is have a Technician perform these diagnostic tests (refrigerant is dangerous; you will be blinded if liquid refrigerant sprays in your eye and if enough liquid refrigerant happens to spray on your skin you can be permanently injured). YourMechanic, being mobile, can come right to your door and take care of it. If the system is low, you might have a leak.

I say "might" because automotive systems are not like the nearly (or actually) hermetically sealed refrigeration systems that you are used to at home. Those systems are NOT supposed to leak at all during normal operation. Auto systems though generally "seep", due to the type of sealing technology (o-rings, etc.) that is used and the harsh operating environment and so although the amount that seeps is very small, over 12 years you WILL lose a certain amount of refrigerant.

If you are lucky, the reason it is low now (if it is low) is due to the normal loss that occurs over many years. If you are not lucky, you have a leak, the magnitude of which can vary quite a bit depending on where it is. In any event, anything is repairable and YourMechanic can both diagnose the current failure, identify any leaks that are significant and ultimately do whatever is necessary to get your A/C system functioning properly. Finally, your car uses a refrigerant that is designated as R134a.

My air is blowing cold-hot-cold-hot-cold-hot…
ANSWER : It is possible that you have a leak in the AC system. There are pressure switches that will turn off the compressor if the pressure is too high or too low. The low refrigerant level could cause the AC compressor to cycle on and off. If you would like to have this done, a certified technician from YourMechanic can come to your car’s location to diagnose the AC system and make the correct repair.

2008 VW Jetta AC not cold
ANSWER : Hi Allen. By far the best way to have your AC system correctly diagnosed is by having an AC inspection completed first. By having one of our professional mobile mechanics come to your location to diagnose the issue correctly, it significantly minimizes the mistakes in completing the wrong service. In your case, the issue could be as simple as needing to have the AC system recharged, or there is an existing leak that needs to be repaired before refilling the refrigerant. Best economic bet is to have the AC inspection completed first.

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ANSWER : Hello! There are a few potential causes of your problem that I recommend inspecting. I would first check the refrigerant levels of the system, to ensure that it has adequate pressure. If the pressure is low, I suggest having a technician inspect the system for leaks; I think this is unlikely, since the AC stopped working so suddenly. The most likely case is that there is an electrical issue, such as a blown fuse or open circuit, although I would also recommend checking the performance of the AC compressor. Please keep in mind that the Federal Government requires all AC work or repair to be done by an EPA-certified technician. YourMechanic can send an EPA-certified technician to the location of your Expedition to inspect your AC system, and recommend the best path to repair.

AC temp knob won’t turn all the way to cold.
ANSWER : Hello. Your blend door is the part of your vehicle that is responsible for blocking off hot or cold air depending on the preference of the driver. The hot or cold knob on your climate control system is connected to a cable that moves the blend door when it is turned. This cable could have and issue or the blend door is stuck in its position. I would recommend having the climate control unit removed from the vehicle so the cable can be inspected. If the cable is faulty, I would recommend having it replaced by a qualified professional in order to resolve this issue. If you need a proper diagnosis for this, a certified professional from YourMechanic can come to your car’s location to inspect the AC system and guide through with repairs.

07 Honda Odyssey. A/C will work sometimes. When working is ice cold. It will sometimes blow cold then warm and then cold again.
ANSWER : Hi there. In most cases, this problem is caused by air flow to the AC condenser. If you have a condenser that is clogged with bugs and dirt this could be the source of your problem as well. It is probably a good idea to have a professional mechanic come to your location to complete an AC is not working correctly inspection.