Ac Compressor Clutch Engages and Disengages – How to Fix?

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An Air Conditioner compressor clutch that engages and disengages repeatedly is a typical indicator that the system of your vehicle is flawed on refrigerant. This issue is disgusting, and experts recommend having the AC unit checked because such a system in such a condition can lead to further damages. I thought you should know that an Air conditioner runs as an enclosed system.

The refrigerant rotates through the machine many times, so checking such parts can be helpful. Besides, an AC has sensors for determining refrigerant’s temperature and pressure, stopping and starting the compressor through engaging and disengaging the compressor clutch. Therefore, let’s explore more about a disengaging and engaging compressor clutch and see what we can do to curb the situation.

Table of Contents

The meaning of an AC compressor Clutch

An AC compressor clutch operates so that it sources power from the engine of your vehicle’s flywheel. It’s controlled and monitored by a clutch system through engaging and disengaging to a cycling shaft with the help of an electromagnetic switch. The clutch and the compressor are the Air Conditioner system’s essential parts of your vehicle. Therefore, these components, plus other vehicle parts, should be adequately maintained to ensure they’re in good working conditions.

How an Air Conditioner Compressor Clutch Operate

You must activate the AC Compressor Clutch of your vehicle whenever you want to use it. The vehicle’s engine is directly connected to the compressor’s pump mot through a belt to operate this compressor clutch properly. Several Car Air Conditioners systems operate using an electromagnetic clutch that engages the compressor to rotate the AC unit.

compressor ac clutch not engaging

This compressor clutch features a friction plate placed adjacent to the electromagnetic coil. So, when engaging the compressor clutch, a current moves via an electromagnetic wave. This action will eventually develop a powerful electromagnetic force responsible for pulling the ring in the friction plates’ direction. It will then engage the pump motor that will run the compressor consequently.

Reasons for engaging and disengaging in AC Compressor Clutch

So why is my AC compressor clutch engaging and disengaging? As I have explained above, an AC compressor clutch that engages and disengages repeatedly is a symptom of faults with the system of your vehicle. The decreased pressure makes the switches misread the refrigerant’s pressures. For this reason, what leads to a short cycle in the Air Conditioner compressor?

Short cycling is one of the significant problems with AC conditioning that occurs mainly when the compressor clutch comes on and then goes off constantly. Multiple conditions can trigger short cycling issues, i.e., obstructed or faulty thermostat, icy coils, leaking refrigerant, too large HVAC system.

Secondly, another reason that might cause an Air conditioner compressor clutch to stop engaging is a blown or faulty fuse. Other factors are naked wires to the clutch coil, faulty clutch coil, low-pressure lockout, and poor ground. More so, Some vehicles experience repeated engaging and disengaging due to faulty evaporator temperature sensors and low-pressure switches.

How can I determine whether my AC Compressor clutch is in good working condition?

If the compressor clutch fails to engage, probably the pump will stop working. With such scenarios, the system will lack refrigerant or coolant to rotate around the AC system and cool your vehicle. Therefore, if you want to know the compressor clutch is operational or not, use the following methods:

  1. Switch ON the AC controls to optimal AC
  2. Start your engine
  3. Closely inspect the front part of the clutch
  4. Up to this juncture, the pulley and the clutch should be rotating
  5. Once you see the pulley as the only spinning component, probably the grip is problematic.

However, if you don’t have enough or the necessary skills to configure such an issue with your AC compressor clutch, seek the help of an expert. Try to employ a Car Diagnostic Tool as a scanning tool. You will have to plug it directly into the dash or your car and pop up issues with your vehicle.

How to fix an Air Conditioner Compressor clutch that engages and disengages

Now that you have enough educational knowledge about engaging and disengaging in AC compressor clutches, the next thing you would wish is how to fix the problem. Follow the following guide to work on the situation:

Step 1: Inspect the compressor’s oil level

You can quickly diagnose this issue since the display glass is visible to spot the oil level. The display glass will show a red line, and an oil top-up is necessary if the level drops considerably. When adding oil, you need to ensure that it’s compatible with the existing one. It would help if you also wanted to ensure that the oil is approved and recommended by your AC system’s manufacturer; get more information from the user manual.

Step 2: Discharge overcharged refrigerant

Once the compressor is overcharged, the unit will read abnormal high pressure. It’s advisable to confirm from your user manual to configure the required operating pressure at the higher pressure side. Draining the refrigerant is necessary once you’ve realized that the refrigerant overcharges the compressor. You may correctly do this with the help of a discharge valve located at the gauge.

Step 3: Too low on refrigerant

Checking the coolant level of the compressor is necessary by inspecting the nature of the pressure gauge. Sometimes the high-pressure side may show too low pressure than expected. Again, refer to your user manual to know the correct pressure level.

Frequently asked questions (FAQ)

How long can an AC compressor clutch stick on engaging?

With a faulty switch, contacts wear rapidly, and only a replacement is required. Averagely, you will have to go for a replacement after 30000 or 40000 miles.

How often should your compressor cycle?

Experts recommend not more than four times within an hour. Such an act will extend the compressor lifespan.


It’s not challenging to diagnose problems with your Air Conditioner Compressor Clutch. You can use the above information to search for the issues and properly work on a Compressor clutch that engages and disengages repeatedly. You can do it yourself, but take your vehicle to the nearest or trusted mechanic if it fails.

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