The AC clutch cycling switch is a very important component to a modern vehicle’s AC system. It is mounted in the low pressure side of the AC system and its purpose is to detect the flow of refrigerant in the system by measuring the pressure.
Where is the low pressure switch located?
The low side service valve is located in the line that runs from the compressor through the evaporator (firewall) and up to the condensor on the low pressure (suction) side of the system .
What is a pressure cycling switch?
The pressure cycling switch controls the refrigeration cycle by sensing low-side pressure as an indicator of evaporator temperature . The pressure cycling switch is the freeze-protection device in the system. The switch is mounted on a Schrader valve on the accumulator.
Which switch is located usually in line with the compressor clutch circuit?
The low-pressure side switch is found before the AC compressor, while the high-pressure switch comes after the compressor.
How do you replace a low pressure switch?
- Step 1: Locate the A/C pressure switch. ...
- Step 1: Disconnect the negative battery cable. ...
- Step 2: Remove the switch electrical connector.
- Step 3: Remove the switch. ...
- Step 1: Install the new switch. ...
- Step 2: Reinstall the electrical connector.
- Step 3: Reinstall the negative battery cable. ...
- Step 4: Test the A/C.
Can I bypass AC low pressure switch?
Under normal conditions the pressure switch doesn’t cycle the compressor. In your case, if your system is working properly, you should be able to bypass the switch temporarily until you can replace it .
How do you test a low pressure switch?
- Inspect the terminals on the pressure switch. ...
- Set the voltmeter or multimeter to display AC volts.
- Touch one of the probes from the meter to either one of the terminals on the pressure switch. ...
- Check the voltage reading on the meter.
What is low pressure switch?
The low pressure switch monitors the refrigeration system for a loss of refrigerant charge , and may also be helpful in stopping the evaporator (indoor) coil from freezing up due to a dirty filter or low airflow over the coil. ... low pressure charge. If either one of these switches trip, the HVAC unit will shut down.
What component Cannot be flushed?
Accumulators, receiver driers, lines and hoses with filters and mufflers CANNOT be flushed and must be replaced.
What are the symptoms of a bad AC pressure switch?
- AC system cutting on and off rapidly. Repeatedly cycling on and off is part of the normal operation of an AC system. ...
- Unable to cool the car. ...
- Compressor not coming on.
Are AC pressure switches normally open or closed?
PRESSURE SWITCHES – NORMALLY CLOSED (NC)
How will air trapped in the A C system affect system performance?
When air enters a refrigeration system, it collects in the top of the condenser and is trapped. ... Air will cause a reduction in condenser surface area , which will cause a high condensing pressure. Air can enter the refrigeration system through a leak in the low side of the refrigeration system.
What is the purpose of a low pressure cutout switch?
What does a Low Cut-Off Pressure Switch do? A low cut off pressure switch turns the pump off in the event that the water pressure in your lines drops lower than the cut-in pressure (low number) .
How do you reset a high pressure switch?
A manual-reset high-pressure switch needs to have an operator manually press a reset button in order to restart the compressor . They are also available with either an adjustable cut-out setting that could be adjusted by a technician, or fixed settings, which cannot be adjusted by a technician.
What causes low pressure lockout AC unit?
When a unit cycles or locks out on the low pressure switch, what should you look for? the most common cause is low air flowacross the evaporator . look for dirty filters, dirty evaporator coil, dirty blower wheel. ... Check the blower motor amperage and compare to the name plate.
