A clutch-cycling switch is used only with fixed orifice-tube systems. The clutch-cycling switch is located
in the low side of the A/C system
, taking its high- and low-pressure signals from the low side of the system. It acts as a low-pressure cutout switch, in addition to cycling the compressor on and off.
What is a clutch cycling pressure switch?
The clutch cycling switch is a
type of device called a transducer
, which changes internal resistance in response to changes in pressure. The clutch cycling switch measures the low side A/C pressure near the evaporator outlet and is often mounted on the accumulator.
Where is the AC 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 are the symptoms of a bad AC clutch?
- The pulley that's attached to your AC compressor may freeze and make a squealing sound when you turn your AC system on.
- Your AC compressor clutch may struggle to engage your AC system's compressor when your AC system is turned on.
What causes the compressor clutch to cycle?
If the evaporator core gets too cold, the pressure of the refrigerant in the sensing bulb drops
. That allows the contacts in the cycling clutch switch to open, which releases the compressor clutch and stops the compressor. As soon as the compressor stops turning, the pressures in the system begin to equalize.
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.
What causes AC clutch failure?
Clutch failure is usually caused by
high pressure or voltage issues, or a combination of both
. … With a wrong charge the pressure switches will cause the compressor to constantly engage and disengage. If there is not enough charge the compressor will overheat due to a lack of oil circulating.
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 I know if my AC high pressure switch is bad?
- 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.
How do I test my AC 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.
Should AC clutch spin freely?
Most AC clutches are
designed to spin freely when disengaged
, and also with the pulley and compressor when those are engaged. If the clutch spins freely at all times, and the compressor never comes on, then it may not be engaging and therefore needs to be replaced.
Can I drive with a bad AC clutch?
You will be
fine as long as you don't need or
want AC in your car. Your AC pulley is a free spinning pulley that has a clutch on it. It will spin freely until you turn the air conditioning on. If the clutch doesn't work properly, you will still be able to drive your car.
Why does my AC clutch turn on and off?
There are several possible causes as to why an air conditioner's compressor would quickly turn on and off. … There could be a short circuit or damaged wire in the electronic components of the compressor or the thermostat.
Mechanical failure
. Any of the mechanical components within the compressor may have failed.
What does high pressure on the low side mean?
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. Your condenser has a cycle that it goes through in order to allow your air conditioning to run properly.
Why does AC compressor clutch engage and disengage?
An air conditioner clutch that repeatedly engages and disengages is usually
an indicator that the vehicle's system is low on refrigerant
. The reduced pressure causes the switches to misread the pressure of the refrigerant. Leaks allow moisture to invade the system as the coolant leaks.
