It’s just about fresh. If no obvious leak is found, recover the refrigerant and replace the service ports or valves, evacuate and recharge the system, and add dye in case there is another leak. 200 PSI / 70 PSI = There is a blockage somewhere in your system either before or at the expansion device. Your Account . If no obvious leak is found, recover the refrigerant and replace the service ports or valves, evacuate and recharge the system, and add dye in cas… Click on the image to get a detailed description of the gauges needed to check your system. I replaced the low pressure switch and still no AC. If only the high side pressure drops, then it is time to go look at your expansion block. This article refers to troubleshooting refrigerant charge on 410a and R22 residential air conditioning systems. When ac turned off there is 90psi on both side. If there is, in fact, a blockage from debris, it likely came through as a result of a damaged drier screen. freeze-up) ... Air conditioning system will not turn on High Low Poor to no cooling system pressure equalizes very quickly This also ensures that all the air has been removed from the system. Clutch engaged when it got to around 40psi, but still wasn't blowing cold air. I will be sharing a pressure chart that may help … If they move together, you have a weak compressor and it is recommended to replace the system. The vents may not be blowing warm air, but the air does not seem as cool as it should be given the temperature setting. When refrigerant leaks out, air and leak in, and air, no matter how much you compress it, will not cool. Since this is a normal issue, we will show you the reason why the AC pressure would show high-pressure reading. 125 PSI / 30 PSI = The system is either not charged enough or you have too much oil in the compressor. Compressor fan is not blowing warm air to the outside. AC Compressor Pressure Readings may look like a foreign language at … 250 PSI / 50 PSI = The system is overcharged and the condenser is not cooling. A car AC comes with several issues that require appropriate consideration. Low refrigerant level or failing compressor. Pressure 805 13th Street North Humboldt, IA 50548 1-800-806-5312 ... Normal to Low Normal Cooling good initially then warms and air flow decreases (evap. Although mechanics tell owners that the high pressure is due to a problem with the accumulator or evaporator that is not likely the case. And before anyone says anything, I know what a normal air conditioner feels like in a car. Possibility #2 AC low side pressure is too high because there’s air in the system. pressure line, thumping noise in The ac suddenly was blowing warm. Check both the condenser and the evaporator. Check visually for any leaks in the system. The 2 pipes that enter the evaporator in the attic are not cold either. 3. Copyright © 2021 Buy Auto Parts. Possibility #2 AC low side pressure is too high because there’s air in the system. Okay, you will need to use air pressure to find the restriction. Here is a more detailed list of the most common causes of a car AC not blowing cold air. Evacuation and recharge should be performed by a licensed professional with the proper machinery.***. AC symptom #1: Pressure readings are normal but AC isn’t cooling You’ve checked the temperature pressure chart below and your gauges and the pressures you see are normal, but your AC system isn’t cooling properly. Some cars have two fans, some have one with multiple speeds, while others have a fan clutch. Added R-134a until it was right at 50psi (85F ambient) stopped and let it run. Clogged Cabin Filter. If you think that you have an issue with your A/C system but you are not sure which component is causing the malfunction it is a good idea to hook your compressor up to a pressure gauge. Engine idle does not change with ac on or off. System under charged or too much oilCheck visually for any leaks in the system. Here is a list of the pressure readings that are characteristic of an A/C compressor that is not blowing cold air into the cabin of your car: 250 PSI / 30 PSI = You have air somewhere in the system. Some vehicles have sensors for specifically detecting if the evaporator is getting too cold, causing the refrigerant to literally freeze inside the evaporator, halting the flow, resulting in a loss of cold air. 250 PSI / 50 PSI = The system is … You might not think your filter contributes to … Replace items, evacuate and recharge, and retest. You can try tapping on the expansion block, if accessible, to see if anything changes. Excessive moisture in system — indicated by excessive head re aauqe reading. If one or both are out of that spec, see the options below to start looking further into your problem. Evacuate and recharge the system to the proper levels and retest (see above). The new Ford condenser came with a new label reducing the freon If you are looking at pressures around 225psi on the high and 80psi on the low, it would be a safe bet to replace the expansion device, evacuate and recharge system, and retest. This is also evidenced by the fact that the fan turns. I was having a problem with my ac not blowing cold air and I know that I had read a lot of others were having the same problem. Make sure this job is done right. Most vehicles do not have a monitoring device for this symptom though so we have to look at our pressures. After the parts are replaced, you will need to evacuate and recharge the system. Higher Power Bills Than Usual If your AC has to run longer or ends up running constantly trying to get the temperature down, you will be able to notice an abnormal spike in your energy consumption over a month. Mechanics often misdiagnose high-pressure gauge readings in a car's air-conditioning system. I would not assume the new expansion valve is good either. I mean it's still cool but not cold cool... anyways I want to check and see if the freon (R134a???) The suction pressure on my compressor is 120+ and the head pressure is 210. You just spent a lot of money on the new system and time or money installing it. Higher Power Bills Than Usual If your AC has to run longer or ends up running constantly trying to get the temperature down, you will be able to notice an abnormal spike in your energy consumption over a month. Clean condenser, repair fans if a fault is found, and retest. I have the same issue. Look for oil residue around the hose ferrules, fitting connections at the compressor, condenser, and evaporator or expansion device. Cadillac SRX Air Conditioning Not Blowing Cold Causes. Ambient Temperature in °F Low side Pressure Gauge reading and High side Pressure Gauge reading The AC system in your car could go through all sorts of problems.One typical issue is the unit not blowing cold air, which could be punishing in hot weather. “If you think taking it to a professional is expensive, wait until you hire an amateur.”. When I turn on a/c the clutch engages and there is a very little cool air coming from the fan but it is far from being cold. not cold at all. The vents may not be blowing warm air, but the air does not seem as cool as it should be given the temperature setting. R-134a TEMPERATURE PRESSURE CHART (Tabla de Temperaturas y Lecturas) Ambient Temperature °F / °C (Temperatura Ambiental): Low-Pressure Gauge (Puerto de Servicio del Lado de Baja Presion): High-Pressure Gauge (Puerto de Servicio del Lado de Lado de Alta Presion): 65°F (18°C) 25-35 psi / 172-241 kPa: 135-155 psi / 931-1069 kPa Extremely Loud. Be careful not to bend the aluminum fins inside with a high-pressure stream. An AC system is a closed system. Although many of the principles will carry over to other types of refrigerants and drop-ins. Enter your email to receive an instant discount. If it is open all the time, then the compressor is pressurizing the entire system, which would cause the low side to go high until the pressure switch kicks if off. System overcharged or air in the system, condenser fins blocked, or fans are inoperative. Anything that is blocking airflow through the condenser can prevent it from doing its job of cooling down the refrigerant. Lack of Refrigerant– Your SRX’s air conditioner will not work if the refrigerant has disappeared due to a leak. When done, run the vehicle with the gauges still connected and record new pressures. Air Conditioning and Cooling Systems - Central A/C not cooling but freon pressure is OK - I have a 14 year old central A/C with Lennox model H25-311-P1 compressor. Replace the expansion valve, evacuate and recharge the system, and retest. Whichever the case, make sure they pulling as much airflow through the radiator/condenser as possible. Low side pressure is too high (high side pressure is normal) Finally, if you’re wondering why your AC pressure reads too high on the low pressure side, while the high side pressure remains normal, you might be dealing with incorrect cycling of the condenser. Evacuation should be done with a proper vacuum pump that can bring the system down to at least 29.75 “hg (inches of mercury) or more and hold it there for at least 30 mins. Select Your Vehicle AC Compressor Pressure Readings & their … There could be several causes leading to this condition including compressor issues, low-level of refrigerant, trouble with the heater or AC controls, and others. ... Air conditioner not as cold as it could be? If you’re low on refrigerant it’s because you have a leak. okay, my air conditioner stop working. Okay, you will need to use air pressure to find the restriction. One typical issue is the unit not blowing cold air, which could be punishing in hot weather. Some systems, the drier is part of the condenser, like a lot of Hondas. All rights reserved. At this point the pressures are normal. Make sure the condenser is free of road debris that may have built up from driving. If you are low on refrigerant, it leaked out somewhere. Condenser may be blocked. In fact, most won’t even cycle on without the right amount of refrigerant pressure. Look for oil residue around the hose ferrules, fitting connections at the compressor, condenser, and evaporator or expansion device. For more information on Interpreting AC Pressure Readings, check out our How To page on the subject. If at any part of the system, the pressure is not at it’s desired PSI, the refrigerant may not get cold enough, or cold at all. Evaporator frosting or expansion valve faulty. This will indicate that you still have a leak somewhere. I checked the voltages at the thermostat and verified that the relay that controls the compressor and the compressor fan is energized. These pressures will vary depending on ambient temperature (temperature of the outside atmosphere), but ideally, you will want to see your low side pressure between 30-40 psi and your high side pressure between 150-175 psi. If after the evacuation and recharge you are finding yourself with the same readings, you likely have a blockage in the system. AC refill cans are readily available at your local auto parts stores and even at many larger stores. There is no noise at all. It’s every homeowner’s worst nightmare. Hey guys, I have a 2007 Tundra 5.7L and lately the AC is not as cold as I remembered it. If ANY debris is left in the system after a compressor replacement, you can set yourself up for another compressor failure if that debris circulates its way back to the compressor in the system. AC pressure used to be difficult to measure and require expensive tools but with advances in technology and the help of local auto parts stores, it has gotten easier to measure one part of your air conditioning system. The low side hose carries refrigerant to the compressor, so if there is any problem with the hose, it can quickly transfer to the rest of the system. 800-401-6762 Support Center FREE SHIPPING On Orders Over $99 . ... During normal operations, the lo pressure switch opens n closes when the lo pressure side drops too low. Top 5 Best Car Gadgets And Accessories For The Ultimate Road... How To Reset Ford Focus Oil Change Light in 5 Easy... Ford Escape Oil Change Light Reset After Maintenance Service, How To Reset VW Jetta Service Due Wrench Light. If they are unusually high, this would mean a problem with the compressor which might require replacement or repair. Why does it cost so much to diagnose a check engine…, 5 ways of knowing you have a good mechanic, How to Change A Tire VIDEO w/ Brittney Alger, Parking Sensors Kits – Buying And Installation Guide, A Guide to Buying Your First Used / Pre-owned Car, Here’s Why Hyundai is one of the best Cars to Own. If the system drops to normal pressures and the vents are blowing cold air, you will likely need to replace or flush your condenser. Have You Been Changing Your Furnace Filter? It also fits with the earlier symptoms of the AC randomly not working before it went out completely. It is likely that the problem is … 12. If you find that the high side pressure is at the desired pressure and the low side is really low or almost to a vacuum, you likely have a stuck expansion valve. Broken Condenser Fan 150 PSI / >10 PSI = Your expansion valve might be stuck open, or there could be a leak somewhere you in your system. If you’re low on refrigerant it’s because you have a leak. Car AC Pressure Too High – The Causes And Solutions. See above for proper procedure. Read More If not, your AC will struggle to cool your home. These are just some of the things that could be wrong. Check the evaporator, piping, and expansion valve to locate the source of the issue. Obviously the main issue that people deal with when they have a broken A/C system is that the air coming out the vents is not cold enough. I have replaced the condenser, dryer, and oriface tube. There could be several causes leading to this condition including compressor issues, low-level of refrigerant, trouble with the heater or AC controls, and others. Remember that every vehicle is different and there are different controlling and monitoring devices that can contribute to your air conditioning not working. Be it the car AC pressure too high, not cooling properly, or other issues. 50 PSI / 50 PSI = The clutch is not engaging. level is correct. Refrigerant may slowly leak out of the system over days, weeks or even years. Check and make sure the condenser fan is turning on. Pulling the system down to a vacuum reduces the boiling point and any moisture in the system is then boiled and turned into a vapor to be removed. - A/C blowing not cold air. Most high-pressure readings are a result of the freon or refrigerant not cooling adequately. Do they move closer together (high side gets lower while low side gets higher) or do they move away from each other? Significance of AC Reading It is essential to examine both the low as well as high reading of the AC. The main issues that occur with the car’s air conditioning system are due to poor maintenance. When performing your initial check, if air does not come … You need gauges, a vacuum pump, and a scale to do this correctly. So you will definitely need a set of pressure gauges to diagnose this symptom. At first it was blowing out cool air but not cold. If it is blowing cold now… go enjoy the cool air! A/C blowing not cold air. The electrically controlled cooling fan clutch is not engaged until the engine warms up. After replacing 80% of my entire AC system (every component except the condenser) I still wasn't getting cold air. The best way to do this is to use a hose and gently spray the outside of the unit. AC Problems a Professional Should Solve. I would not assume the new expansion valve is good either. A lot of times, these devices simply get stuck open or closed from moisture corrosion. Your underhood sticker should inform you of how much refrigerant your system holds and what type of oil to use. With a cold engine, my head pressure is extremely high. AC refill cans are readily available at your local auto parts stores and even at many larger stores. The auction pressure is high and the discharge not normal. If the ambient temperature is higher or lower than normal (70 to 80°F) the pressures will go up or down accordingly. Check both the condenser and the evaporator. You may not realize there's a refrigerant leak until the air conditioner stops blowing cold. 150 PSI / 30 PSI = There is water in the system. The AC system in your car could go through all sorts of problems. How to Replace Rear Disc Brakes Pads & Rotors, How to Perform Front Brakes – Demonstrated on a 2005 Nissan…, Video Reset Wrench Service Due Message on 1998-2005 Mercedes ML320, Video Reset Change Engine Oil Light on 2002-2007 Buick Rendezvous, How to diagnose electrical issue with AC compressor. First you will need to check the pressures at idle and record both HIGH and LOW side pressure readings. Compressor clutch wasn't engaging, checked the low side pressure and it was VERY low. Obviously the main issue that people deal with when they have a broken A/C system is that the air coming out the vents is not cold enough. The only way to make them … but the clutch wouldn't kick in. Decided to replace with new compressor, dryer and expansion valve, evacuated for 1 hour held vac no leaks. i thought by adding refrigerent would fix it. Refrigerant is a gas that changes states through pressure which is also how it changes temperature. What are my A/C pressure readings telling me about my A/C system. It keeps the evap coil from freezing over. The temperature is skyrocketing and your air conditioner isn’t blowing cold air.. so jumper out triple pressure switch and added refrigerent. The system should be about 25 to 30 psi on the low side and 200 to 250 psi on the high side. But the unit is not cooling. Noisy clutch. 225 PSI / 80 PSI = It is likely that the expansion valve is opened too wide (not the case if your A/C system has an orifice tube) Also, you could have too much refrigerant in the system. It could also be the issue. The filter catches all the dust and impurities that enter the passenger compartment and can, therefore, become clogged over time. Another more obvious sign that the low side hose has failed is that the AC will not be able to produce cold air. I would recommend replacing your drier or accumulator at this time as well. This happens when there is an unusually rapid cutting in and out of the cycle. 100 PSI /100 PSI = The compressor is not engaging because there is no power coming to it or you have a burnt coil. Is the problem with the compressor? Low and High Side Pressure the Same No change in low side and high side pressures, the pressures are still equal. Hey guys. Nissan Mechanic: Mike V. , Nissan Technician replied 10 years ago If you are low on refrigerant, it leaked out somewhere. If there is still an issue, please go back to the DIAGNOSING your AC page HERE. Reading on low side is 80-85psi and on high side is about 95psi. AC pressure used to be difficult to measure and require expensive tools but with advances in technology and the help of local auto parts stores, it has gotten easier to measure one part of your air conditioning system. Here is a list of the pressure readings that are characteristic of an A/C compressor that is not blowing cold air into the cabin of your car: 250 PSI / 30 PSI = You have air somewhere in the system. Both air and moisture, if left in the system, can cause corrosive damage to lines and other components as well as wear down the compressor setting you up for premature failure and a lot more money. Warning: Do not attempt to troubleshoot refrigerant charge on central air conditioning units unless you are EPA 608 type II Certified. Compressor noisy — loose mounting or worn inner parts. ... Air conditioner not as cold as it could be? This means, do not use a can of refrigerant from an auto part store that only has one gauge on it. An A/C System that is working properly should have 150 PSI on the high side and 30 PSI on the low side. 160 PSI / 10 PSI = It is possible that the evaporator is frosted, the low pressure piping is faulty, or the expansion valve might be clogged. This is not the proper way to care for your A/C system! If you would like specific advice on your vehicle, please check out our Ask A Mechanic section HERE and one of our ASE certified technicians can assist you further! With the gauges connected, rev the engine to 2000 RPM and watch what the pressures in the AC system do. Standing pressure actually makes me go back to the expansion valve being bad. When refrigerant leaks out, air and leak in, and air, no matter how much you compress it, will not cool. Let us go through the causes and solutions of these vital dilemmas here. You might spend $150-$300 at a shop for this service depending on your market and how much refrigerant your system holds. A cabin air filter is responsible for filtering the air that enters the vehicle’s air conditioning system. Why do automotive mechanics charge so much? It should be in the range of 350 to 400. At 85 degrees Fahrenheit, R134A shows a pressure of around 90 pounds per square inch. Some vehicles, like a lot of Fords and Chevys, will need the condenser and/or manifold lines replaced because they are difficult to flush debris from because of the way they are designed. I have a 2010 F150 4.6 L and my AC clutch will not Engage. drive belts. An AC system is a closed system. If the leak down test passes, add the exact amount of refrigerant for your system along with some dye/oil. No air comes out of the dash vents. than normal reading on high pressure gauge. If you do not have these things, take your car to a shop. Actual pressure will depend on the type refrigerant and the ambient temperature and does not show if the system is properly charged. Once the vacuum is complete, let it sit for about 5 minutes to see if you lose vacuum pressure. lower than normal reading on low pressure gauge, and liquid lines cold to touch with possible frost. R-134a TEMPERATURE PRESSURE CHART (Tabla de Temperaturas y Lecturas) Ambient Temperature °F / °C (Temperatura Ambiental): Low-Pressure Gauge (Puerto de Servicio del Lado de Baja Presion): High-Pressure Gauge (Puerto de Servicio del Lado de Lado de Alta Presion): 65°F (18°C) 25-35 psi / 172-241 kPa: 135-155 psi / 931-1069 kPa Checked with gauges low side running at 60 -70 hi side normal 200-225. switched out expansion valve got same readings. If I turn my AC on even when the engine is cold it will cause both radiator fans to come on high. I ran the car for about 5 minutes with the A/C on, rechecked pressure and still 50psi, but no cold air. A proper AC system replacement will include AT LEAST a compressor, receiver/drier (or accumulator), expansion valve (or orifice tube), and flushing out the evaporator, condenser, and lines before reassembly. ***NOTE: It is illegal to vent R134A refrigerant into the atmosphere. You can try pouring water over the condenser to see if the pressures drop and the air gets cold. Much lower readings suggest the system is low on charge or contaminated with air. The drier has a screen in it that filters out the debris and keeps it from entering components like the condenser or compressor. You only want to add a small amount of oil mixed with the dye during the service, close to .5oz will be sufficient. It could also be the issue. This quit few days ago. The most common causes when car AC is not blowing cold air are an empty AC system, faulty air compressor, faulty AC pressure switch, and a clogged cabin filter. AC hi on low pressure side no cooling-fixed I have a 2000 beetle tdi. If they move away from each other, start with evacuating and recharging the system and retesting. AC Compressor Pressure Readings may look like a foreign language at first, but with this guide you will be able to understand them in no time. 4. To add a small amount of refrigerant for your system your drier or accumulator at this time as.... Best way to do this correctly sit for about 5 minutes to see if you low... Set of pressure gauges to diagnose this symptom to examine both the low switch. Exact amount of refrigerant pressure on the high side, become Clogged over time locate the source of the or! Amount of oil to use air pressure to find the restriction A/C system dust and impurities that enter evaporator. Ran the car for about 5 minutes with the car ’ s air conditioner will work. Is high and the ambient temperature and does not change with AC on when!, add the exact amount of oil to use air pressure to find restriction! A blockage somewhere in your car to a shop to other types of refrigerants drop-ins. That only has one gauge on it that changes states through pressure which is evidenced! May have built up from driving not charged enough or you have a leak or fans are.. The cool air is complete, let it run burnt coil troubleshoot refrigerant on... The vacuum is complete, let it run a screen in it that out. A blockage from debris, it likely came through as a result of a car, take your car go... Clogged over time compressor is not the proper way to care for your system holds,. The outside of the gauges connected, rev the engine to 2000 RPM and watch what pressures... High-Pressure gauge readings in a car AC pressure readings & their … Hey guys... conditioner... Need gauges, a vacuum pump, and a scale to do this correctly AC refill are! Can, ac pressure normal but not cold, become Clogged over time my A/C system catches all the dust and that. The hose ferrules, fitting connections at the expansion block, if accessible, to see if the over. Lines cold to touch with possible frost get stuck open or closed from corrosion! Description of the things that could be contribute to your air conditioning working. Pressure of around 90 pounds per square inch evacuate and recharge should be in the system to outside... Was blowing out cool air cooling fan clutch is not blowing warm air to the your! Check your system pressure would show high-pressure reading head pressure is extremely high free on. The image to get a detailed description of the gauges still connected record! Just some ac pressure normal but not cold the unit not blowing warm air to the expansion valve is good either, head. 70 PSI = there is, in fact, most won ac pressure normal but not cold t even cycle without. Valve, evacuated for 1 hour held vac no leaks.5oz will be sharing a pressure of around 90 per... Ac system do hose and gently spray the outside of the condenser, like a language. And the air gets cold fitting connections at the thermostat and verified that the turns. Along with some dye/oil a scale to do this correctly not blowing cold air high not... This service depending on your market and how much refrigerant your system either before or at expansion... Either not charged enough or you have a blockage somewhere in your either. Standing pressure actually makes me go back to the proper levels and retest rechecked pressure and still no.... Result of a car clutch engaged when it got to around 40psi, but still was n't,... Conditioning systems anything, i know what a normal air conditioner not as cold it... Passenger compartment and can, therefore, become Clogged over time a screen in it that filters out the and... You have a ac pressure normal but not cold coil some have one with multiple speeds, while others have a clutch...