What are my A/C pressure readings telling me about my A/C system?

If you suspect a problem with your air conditioning system but aren’t sure which component is to blame, you should connect your compressor to a pressure gauge. Obviously, the biggest problem that individuals have when their air conditioner breaks is that the air coming out of the vents isn’t chilly enough. Here’s a list of pressure measurements that indicate an A/C pressure that isn’t pumping cold air into your vehicle’s cabin.

Pressure system

Pressure in the AC system and temperature have a relationship between them. A chart showing temperature can be used to compare the A/C pressure of the refrigerant at the given temperature. Since there is no way to determine how much refrigerant is left in the system without opening and measuring it, we will use pressure and compare it to a pressure-temperature chart?

  • Connect the system to the pressure gauge.
  • The pressure should be equal in both high and low readings.
  • Take a temperature reading.
  • Is the pressure in accordance with the pressure-temperature graph?
  • The temperature should be consistent with the chart, indicating that the refrigerant level is adequate.

Higher A/C pressure

When the pressure gauge shows increased pressure on both the high and low sides, it might indicate that the airflow condenser is malfunctioning.

  • Check to see if the cooling fan is operational.
  • Check to see whether the condenser fan is bent or filthy.
  • Examine the condenser fan for any obstructions.

Low A/C pressure

  • Lower high and low pressures suggest that there is an issue with pressure accumulating inside the system or that the condenser is removing too much heat.
  • Place a fender cover over the condenser and check the temperature while the engine and AC are running.
  • The compressor may be worn out if the pressure does not rise.
  • If the cooling fan is constantly on.
  • Sides with a lower low and a higher high
  • If the readings are lower on the low side and higher on the high side, it implies that something is blocking or closing the orifice tube. If the temperature in the orifice tube drops, try touching the lines.
  • Sides with a higher low and a lower high
  • It implies there is too much refrigerant going into the evaporator for it to manage.
  • It is not sensing the temperature adequately because the TXV is open or the thermal bulb is broken.
  • There is a big gap someplace in the orifice tube, or the o-ring sealing outside the orifice tube is not sufficiently sealed.

The following is a collection of readings that describe the issues associated with a malfunctioning air conditioner.

High-100 PSI Low-Low PSI-

When the compressor isn’t getting enough power or has a burned coil, this reading appears. This occurs as a result of inadequate system maintenance or an acid reaction inside the system, resulting in a burned coil. 

You’ll need to replace the burnt coil with a new one to repair this problem, and your air conditioner should operate perfectly after that.

Low-30 PSI, high-250 PSI-

There is a leak of air someplace in the system. Go to a mechanic and explain the situation. One of the most prevalent causes of a car’s air conditioner not working correctly is air leakage. It occurs as a result of normal wear and tear as the vehicle ages.

Low-50 PSI, high-250 PSI-

The condenser is overcharged or overheated because it is unable to adequately cool down. It’s possible that something is blocking the condenser, which is preventing it from cooling down.  By eliminating heat from the refrigerant, the condenser converts it from a gaseous to a liquid form; if the condenser is clogged, the AC will not blow cool air. If you’re having trouble with your vehicle.

Low-80 PSI-high-220 PSI-

Because the expansion valve is excessively broad, this happens ( this is not a problem if your car has an orifice tube). Another factor that might be creating this issue is that your air conditioner has too much refrigerant. Try not to tweak the valve because it is simply a temporary fix; instead, consider replacing it.

Low-70 PSI, high-200 PSI-

This signal appears when there is a clog in the system that is interfering with airflow and preventing the AC from adequately cooling the vehicle.

Low-10 PSI, high-160 PSI-

When the expansion valve is jammed, the evaporator is frozen, or the piping pressure is low, this reading appears. Check these sections on your own or with the aid of a professional technician to determine the cause of the problem: expansion valve, pipe, and evaporator. It implies there aren’t enough refrigerants in the system, which leads to overheating and other issues if the valve is clogged.

Low-30 PSI-high-150 PSI-

this reading is displayed When there is water in the system. If you notice water draining from your automobile, it is entirely normal and a good indication. The issue arises when you don’t observe water draining outside your automobile and instead encounter water straining within your vehicle. It simply implies that there is water in your system that cannot drain owing to a variety of factors.


There are a variety of reasons why your car’s air conditioner isn’t operating correctly. you can quickly determine the root of the problem by utilizing an A/C pressure gauge and a temperature chart to determine what is causing your air conditioner to run inefficiently or not blast out cold air. You can also read Car AC Compressor Cost, Car AC Condenser, Air Conditioner Blower, AC Control Units.