All Rights Reserved. If you are low on refrigerant, it leaked out somewhere. Getting your air conditioner serviced, especially if you need to drain the refrigerant and put new stuff in, is something that has to be done using the exact right tools by a professional. The compressor is the part of your air conditioning system that actually creates the pressure that the. They usually have a label on them that warns you not to eat them. If the switch fails, then this is not able to happen and it can result in your pressure being thrown out of whack. If the system is continuing to cool it may be doing so at reduced capacity, observed as a loss of up to … 2) Low refrigerant charge (most common cause). An automotive air conditioner is a system which cools and dehumidifies the interior of a car, bus or truck ... High Side: Low Side: Low Low High Side: High Low Side: High High Side: Normal Low Side: Normal ... indicated by too high a low gauge reading and excessive sweating of evaporator and suction line. The air conditioning system in any car is one of the most finicky systems that you have. or so if you want to do this yourself. why? Possibility #3 AC low side pressure is low because of a restriction on the high side. If you use your gauge and determine that your low side is up over 100 and your high side is down around 150 then odds are a mechanic is going to tell you that the problem you're dealing with is your compressor has failed. In most cases, their diagrams are right from the factory manuals. If you are experiencing a problem with how your AC works, but you also have these normal ranges of low pressures on the low side and high pressures on the high side then it means you have a problem somewhere else in the system. Alldatadiy.com, on the other hand, uses the factory diagrams. A/C compressor goes on and low side goes into vacuum. As we've established, there are two different sides to your AC system that have two different pressures. If the pressure is high when it's running, then that might just be normal operating procedure. Let’s Find Out The Pros and Cons Of Each! Your expansion valve is located at the evaporator and regulates the flow of refrigerant through the AC system as a whole. If the expansion valve fails then the coolant levels can be thrown off. 3) The heater core is leaking warm coolant into the heater box. 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. However, I noticed on the AC gauge manifold that the low pressure side consistently reads too low while the high pressure side reads too high. 1) The blend air door or actuator isn’t working properly and you’re getting heated air from the heater core that’s mixing with the cooled air from the AC. From that point all you need to do is compare it to the ambient temperature and the pressure is listed on the number chart for your particular air conditioning unit. The pressure is going to need to be released somehow, and it's best to leave that to a mechanic to get the job done safely and properly. . However, if there’s a restriction on the high side of the system in the receiver/dryer, a crimped tube in the condenser or crud accumulation in the condenser or the expansion valve or orifice tube, there’s … That way you can at least tell for yourself that this is the main issue and not one of the other host of issues that could potentially cause problems with your car's air conditioner. It has something inside of it called a desiccant, which is similar to those little packets, but you might find in a pair of new shoes or other products that are meant to stay dry. The pressure on the low side reads 35 PSI while the high side reads 275 PSI! The point of the switch is to turn off the compressor to prevent damage if the pressure is too far out of line for the system. Fix: Remove excess refrigerant or evacuate and recharge with the correct amount. To know for sure that this is the problem you do need to test it when the engine isn't running as pressure goes higher when you do have the engine on, as they're supposed to. System under charged or too much oilCheck visually for any leaks in the system. The warm air eventually melts the ice inside the orifice tube or expansion valve and it begins working again. It's possible that you might have a problem with your. Although there are a number of reasons that can make your low side pressure go too high, and the high side pressure go too low, when it comes to both of them happening at the same time you have some limited options. 1. A new compressor may cost you a couple hundred dollars to buy and get repaired. Install an in-line filter to prevent re-occurrence. Items to note:-it does cool OK, but given that it's only low 80s now, I can tell it should do more The expansion valve controls the flow so that it stays at optimal levels and keeps the evaporator temperature where it needs to be. That saves a lot of time because you don’t have to refer back to the component locator or circuit locations. Let us go through the causes and solutions of these vital dilemmas here. Determining the pressure in your AC system is not entirely difficult to do. Check again when the temperature rises. : It's possible that you have debris blocking the airflow that's coming from your condenser fan motor, or it's possible the motor of the. That in turn can lead to problems with your AC compressor, the expansion valve, and of course the issue with your low side pressure being too high, and your high side pressure being too low. The system is overcharged. Check condenser fan operation. The expansion valve failing is another thing that can cause the pressure on the low side to go too high and the high side to go too low. This could be the result of a problem with your thermostat switch or temperature gauge but you're going to need a mechanic to diagnose this one properly for you. 2. R134a Pressure Gauge Chart This chart details how ambient temperature correlates with the system refrigerant charge pressure, and how it affects high and low side psi readings. I hope that refrigerant didn't contain sealant, because that is death to an a/c system. Ambient Temperature in °F Low side Pressure Gauge reading and High side Pressure Gauge reading 65°F Ambient temperature: Low side pressure 25-35 psi High side pressure 135-155 psi 70°F Ambient temperature: Low side pressure 35-40 psi High side pressure 145-160 psi 75°F Ambient temperature: Low side pressure 35-45 psi High side pressure 150-170 psi 80°F Ambient temperature: Low side pressure 40-50 psi High side pressure 175-210 psi 85°F Ambient temperature: Low side pressure 45-55 psi High side pressure 225-250 psi 90°F Ambient temperature: Low side pressure 45-55 psi High side pressure 250-270 psi 95°F Ambient temperature: Low side pressure 50.55 psi High side pressure 275.300 psi 100°F Low side pressure 50-55 psi High side pressure 315-325 psi 105°F Ambient temperature: Low side pressure 50-55 psi High side pressure 330-335 psi 110°F Ambient temperature: Low side pressure 50.55 psi High side pressure 340.345 psi. The system should be about 25 to 30 psi on the low side and 200 to 250 psi on the high side. How can you tell when a system is low on refrigerant? Experts suggest using an IR heat gun or similar tempeature measuring tool to check the tempeature of the refrigerant line on each side of the valve. Eautorepair.net redraws factory wiring diagrams in color and includes the component, splice and ground locations right in their diagrams. (very common especially if you’ve tried to add refrigerant yourself). In other words, the evaporator core ices up and stop cooling. Be it the car AC pressure too high, not cooling properly, or other issues. fan itself has been damaged somehow. Low side pressure at 50-55psi could be low charge, overcharge, bad compressor, weak compressor, low air flow over condenser, stuck open expansion valve, or many other things. The only way to properly charge the system is to remove the refrigerant, vacuum down the system, and then charge it with the specified amount of refrigerant. When you measure the high-pressure side of your air conditioning system you should be getting anywhere between 200 pounds per square inch and 250 pounds per square inch. Consider this scenario: A service technician installs gauges and thermistors on an R-134a, closed-door, medium-temperature refrigeration system, incorporating a liquid high-side receiver and a thermostatic expansion valve (TXV) as the metering device. aircon is not cold. Running a system check can determine whether that’s the case. If the expansion valve fails then the, What Happens When Your Heater Core Goes Out? This can essentially destroy your entire air conditioning unit. On a properly working system, high-side pressure will be about twice the ambient temperature, plus 50 PSI. The best way for you to tell if you have a problem with the low side being too high in your air conditioner and the high side being too low is  by the pressure gauge that we linked to above. If you’re tracking down a wiring issue, Eautorepair.net is the better choice. Blockage on the high-pressure side of the system between the compressor and condenser but before the high-pressure port. The air conditioning system in any car is one of the most finicky systems that you have. Therefore, you should get this part replaced or checked by an experienced mechanic. , your expansion valve, or the receiver / dryer also. If the condenser runs through this cycle more quickly than it's supposed to then the pressure on the low side is going to increase more than is normal. 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. Compressor disengaging because of too high of pressure on the high side and too high of pressure on the low side (up to 70psi and … read more If both of your numbers are in these ranges, then everything is working the way it should be and you shouldn't have too much to worry about in terms of your AC system. The pressure will cycle between the low and the high sides, so wait till it clutch engages to get the correct readings. There are a few too many variables for this one to just be handled on your own, or for the reason for this problem to be refined down more than what we've said. The expansion valve failing is another thing that can cause the pressure on the low side to go too high and the high side to go too low. Pressure that is too much lower or higher shows there is a problem. Liftgate Glass Support Strut Replacement Cost – The Labor Only Takes A Few Minutes. Traction Control Switch Replacement Cost – This Quick Fix Is Less Than $100! And for a lot of drivers this is something they may let slide for a while since air conditioning is not required for the proper functioning of a vehicle. Car AC Pressure Too High – The Causes And Solutions. The expansion valve failing is another thing that can cause the pressure on the low side to go too high and the high side to go too low. High side should be (tempurature of the day) +100psi (+ or - 25psi) Low side should be close to outlet tempurature at the center vent (35-40°F) so 35-40 psi. Evacuate the system and recharge with the correct amount of refrigerant. manifold gauge shows vacuum on low side and no pressure on high side. It's also possible that air has gotten into the coolant system and is raising the pressure as well. Low head pressure may occur simulataneously with high pressure on the suction side of an air conditioner, heat pump or refrigeration system compressor system. If the high side pressure drops from around 150-200 to around 28-psi quickly and then falls gradually after that, you’ve got air in the system. Refrigerant is undercharged; Excessive condenser water flow; Condenser outlet water temperature too low; Air conditioner unit is over capacity; Ineffective compression of compresor or valve is damaged; Ambient temperature too low; Low Pressure Side Too High. If the pressure on the high side and the low side match what is recorded for the ambient temperature around your air conditioner then you don't have a problem with the pressure of your coolant. The compressor is the part of your air conditioning system that actually creates the pressure that the coolant is under in your vehicle. Engine coolant levels will be low. © 2020 Cash Cars Buyer. Generally, these can be found online, and you may also be able to find the correct pressure listed in the owner's manual for your car. This can essentially destroy your entire air conditioning unit. Second symptom: 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. Obviously, this would be a clear place to look if there's a pressure issue in your AC system. The car will not turn the AC compressor on, probably because these pressure are out of wack. : The other reason you might be experiencing high pressure is even when the engine is off is that your whole air conditioning system has been overcharged. The pressure switch is mounted on both the high and low sides of your air conditioning system and it monitors the pressure of the refrigerant as it travels through. There can be a number of problems that crop up with air conditioning not working at all to working at a diminished capacity. But if you see the AC low side high, high side low , such as the low side is 100 and the high side is 150, there might be problems with any of the inner components. Look for oil residue around the hose ferrules, fitting connections at the compressor, condenser, and evaporator or expansion device. You can buy an AC pressure gauge on Amazon for about $30 or so if you want to do this yourself. You just need to hook up a gauge set to the AC system and record the pressures on the low side and the high side. The expansion valve controls the flow so that it stays at optimal levels and keeps the evaporator temperature where it needs to be. If it's not the compressor that's causing trouble for your AC pressure, it may be your pressure switch. Your expansion valve is located at the evaporator and regulates the flow of refrigerant through the AC system as a whole. If you're finding that the low side pressure is higher than it should be while the high side pressure is about normal, then you're probably having an issue with your condenser. This will reduce the airflow through the condenser and that in turn means it's not going to be able to cool down the AC system. The desiccant in your AC unit does the same job. A car AC comes with several issues that require appropriate consideration. Once it circulates back to the compressor it is repressurized as the whole process continues. Some of them can be quite a bit more expensive, but if all you're doing is simply checking the pressure that should get the job done for you at a fairly reasonable price. 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. This could be normal if outdoor temps are very low. Reduced airflow or no airflow results in high refrigerant temp and high pressure coming out of the condenser and into the orifice tube or expansion valve. It can be used for recharging refrigerant, or to diagnose an a/c system based on pressure readings from your gauges. So you have to refer to the factory legends to learn the identification symbols and then refer back to circuit diagrams to find the splice and ground locations. 2013 Ford Escape Problems – What You Need To Know! You can buy an AC pressure gauge on. Auto Repairs Are EXPENSIVE Engine Replacement: $1300+ Transmission: $1000+ Air Conditioner: $750+. If you have too much, going through the system it could end up freezing and if there's too little then the evaporator may overheat and cause damage. 5. Anyway, I hooked up my manifold gauges and the low side pressure maxed out the gauge! The high side pressure was roughly 150. There can be a number of problems that crop up with air conditioning not working at all to working at a diminished capacity. Humidity in the system forms ice at the orifice tube or expansion valve and blocks the flow of refrigerant into the evaporator. You just need to hook up a gauge set to the AC system and record the pressures on the low side and the high side. Cool Automotive Products and Tool Recommendations, Read AUTO REPAIR ARTICLES sorted by topic, Compressor clutch not engaging after blower resistor replacement, Initialize Ford auto up/down one-touch feature, Custom Wordpress Website created by Wizzy Wig Web Design, Minneapolis MN. Yo… Possibility #3 AC low side pressure is too high because the condenser has reduced airflow. This is the second part of a series on AC pressure gauge readings. An A/C System that is working properly should have 150 PSI on the high side and 30 PSI on the low side. The reason you have a high pressure side and a low pressure side at all is because the compressor increases the pressure and as it runs through your AC system to the condenser where it changes from a gas to a liquid and it will eventually lose pressure again as the cooling process takes place. Replace expansion valve, flush and install in-line filter. l. Defective winding Or I'm guessing there is a restrict somewhere. After doing a vacuum test and not having a leak, then recharging it and having the high pressure line pressuring, yet the low side didn't change. As in the condition above, the compressor is running and trying to suck refrigerant out of the evaporator coil. Obviously, this would be a clear place to look if there's a pressure issue in your AC system. 3. For example, it is currently 81 degrees outside. If nothing else, then you have eliminated this issue as the source of your problem so it's not entirely a waste of time to check it out even if it isn't the issue that you're facing. Fix: Replace a bad blend door actuator or faulty heater control valve or repair a faulty blend door or blend door linkage. If you need to dig into your doors, dash or console, Alldatadiy.com is the better choice because Eautorepair.net doesn’t any interior or exterior trim or body part removal. If your compressor it's not working the way, it's supposed to then obviously the pressure in your AC system can be severely compromised as a result. Pricing: ---Eautorepair.net--- 1 month subscription $19.95 per vehicle 1-year subscription $29.95 per vehicle 4-year subscription $44.95 per vehicle ---Alldatadiy.com--- 1-year $29.95 subscription: additional vehicles $19/95 each 5-year $49.95 subscription: additional vehicles $34.95 each Which one should YOU choose? Once you know that your pressure is off and that's the reason your air conditioning is not working the way it's supposed to, then you should hopefully be able to troubleshoot one of the causes that we've gone through which led to this pressure imbalance in the first place. 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Disassembly instructions for interior trim panels and exterior items like headlights and tail lights make putting! Normal if outdoor temperatures are very high is higher or lower than normal ( 70 to 80°F ) heater...