The only accurate method to recharge an automotive a/c system that requires a critical charge is to weigh the refrigerant (Freon) into the system using a manifold gauge set and calibrated special scale for this purpose. Recharging the a/c system by pressure, which is the method used when the system is recharged using small refrigerant can and a gauge is inaccurate, and virtually impossible to charge the system according to manufacturer specifications. Depending on the a/c system design, the pressures will be impacted by the type of compressor, metering device(Expansion Valve or Orifice tube) ,ambient temperature and humidity. Pressure controlled systems could reach pressure cycling points faster ,increasing the compressor clutch cycling and forcing the compressor to operate under higher-than-normal crankcase temperatures if the system is undercharged. Short cycling compressors will decrease the life of the compressor clutch assembly, due to more often engagement and disengagement of the clutch assembly and the compressor pulley. When the system is overcharged the evaporator will not be able to evaporate the refrigerant metered by the metering device and liquid refrigerant could reach the a/c compressor. An overcharge system will force the a/c component working pressures to the limits and could develop leaks and cause compressor damage.
Car A/C system Recharge near me
Improperly recharged car a/c systems will increase or decrease compression ratios, negatively impacting the overall health of the a/c system. Just because the air conditioner is blowing cold air, it doesn’t mean is working according to manufacturer specifications. Modern car a/c systems design have the capability to adjust their operation even when the freon recharge is not 100% accurate. The a/c system will change compressor displacement, thermal expansion valve operation ,condenser fan speed and will force the system to get to the desired temperature set by the driver. Car a/c systems working under inaccurate freon charge will have compression ratios that will stress the compressor and shorten their life. The manufacturer calculated values of superheat and subcooling happening in the evaporator coil and condenser coil will change, making it harder for the metering device to respond to the flow of refrigerant and for the compressor to receive refrigerant oil back from the evaporator needed for internal piston lubrication. Flash gas rates will be higher at the expansion valve making the valve less efficient.
Ac freon recharge near me
You will need an AC freon recharge if the system is low or after any repair that involves opening the closed loop sealed air conditioning system is performed in your vehicle. A low freon charge could be the result of a leak in any component of the car ac system. Properly fixing a low freon condition involves more than just recharging the a/c system. If there is a leak in the system it must be fixed, otherwise the freon charge could only last couple hours or days before it is low again. Refrigerant leak and refrigerant oil leak happen together ,just at different rates. Recharging the freon in the car ac system without balancing and recharging the oil will lead to compressor failure.
Auto A/C Compressors have evolved over time and the old, fixed displacement compressor has been replaced by more efficient variable displacement compressors. Pressure controlled variable displacement compressor and Electronically Controlled Variable Displacement Compressor (ECV) react in different ways compared to fixed displacement compressors when air conditioning restrictions and other common automotive a/c faults happen. Failure to identify the type of a/c compressor in the vehicle at the beginning of the diagnostic procedure could lead to unnecessary, expensive and in most cases time consuming repairs. A restricted Thermal Expansion Valve creates Manifold gauge readings that could lead to chasing a/c system leaks, unnecessary auto a/c compressor and sensor replacement.
How do I know if my compressor or expansion valve is bad?
Manifold Gauge readings
Low side LOW High side LOW
A restricted Thermal Expansion valve gauge readings will be different in the newer Pressure controlled variable displacement air conditioning compressor.
When a restriction in the refrigerant flow caused by a Thermal Expansion Valve (TXV) fault happens, the Pressure controlled variable displacement compressor will try to compensate the change in refrigerant pressure from the TXV by adjusting the compressor internal control valve, and keep the compressor crankcase pressure at a value where the swash plate angle based on the low side pressure is prevented from going into the condition where you see a manifold gauge vacuum reading. The manifold gauge reading in this type of system will show Low side gauge reading low and High side gauge reading low. It could be erroneously diagnosed as a weak compressor problem.
Low Side into Vacuum High Side LOW
A restricted Thermal Expansion Valve (TXV) gauge reading on an Electronically Controlled Variable Displacement Compressor will be different due to the logic the Powertrain Control Module uses to operate and control the a/c compressor. The PCM will receive inputs from the evaporator temperature and will command signals to the ac compressor electronic control valve to adjust pumping capacity accordingly. When the TXV fails or is restricted the evaporator temperature will increase and that increase value will be sent to the PCM which in turns will increase compressor pumping capacity to 100%.The Electronically Controlled Variable Displacement Compressor will operate similar to an old ,Fixed Displacement A/C Compressor and the Manifold Gauges will show Low Side going near 0 Psig or into a vacuum reading.
How do I know if my compressor or expansion valve is bad?
The type of system must be identified
The type of a/c compressor must be identified
Manifold Gauge Readings must be checked
PWM signals to the ECV must be inspected
Avoid unnecessary expensive repairs.
The air entering the cab is only slightly cool, and there are bubbles visible in the sight glass. there is usually about an 95% chance the restriction is expansion valve failed in the closed position related, 4% chance it is drier related and 1% chance it is somewhere else along the system or an internal drier desiccant bag rupture leading to a/c system contamination and restricting the metering orifice of the expansion valve.
The sun load sensor function as an input for the module in charge of automatically controlling the headlight operation and air conditioning system control module.
How to test the Sun Load or Ambient Light Sensor ?
A bright LED light may be used to artificially force the sensor to adjust for light intensity and angle. With the headlights in the automatic setting position, we should see the running lights coming on and off and the automatic climate control adjusting the air temperature out of the vents. Exposing the sensor photocell to the strong led light will increase the current flow from the sun load sensor while covering the sensor photocell will decrease the current flow signal to the hvac control module and headlight control module. With a scan tool connected to the vehicle or a multimeter we should be able to see these variations in voltage when the sensor is operating properly. The most common voltage range is between zero and five volts, but is always a good idea to compare the readings against manufacturer specs.
Do you need Assistance with your Sun Load Sensor ?
Varying amounts of exposure to sunlight will modify its electrical return signal to the programmer to adjust system output toward cooler air; less sunlight will cause the programmer to adjust system output toward warmer air. Some multizone climate control systems have more than one sun load sensor.
Solar Sensor, Sun load sensor or Ambient light sensor.
The solar, sun load sensor, or ambient light sensor detects the heat load of the sun, elevation and azimuth. It is used to adjust the amount and direction of the cooled air through the dash vents and to control headlights operation of the vehicle.
Do you need assistance with the sun load sensor in your car ?
