Updated at: 30-08-2022 - By: Lucas

Your car’s AC compressor clutch may need to be manually engaged at some point. An issue with the AC compressor could be to blame for this.

Connecting a jumper wire directly to the compressor’s wire is the best technique to manually engage an AC compressor clutch. Before you begin, make sure to check your refrigerant levels and to add oil to the compressor as necessary.

In this article, we’ll show you how to do it step-by-step. It’s critical to remember that this step should only be taken if all other attempts to diagnose the problem have failed. There is no time like the present to begin!

How Does An Car AC Unit Work?

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Components of an air conditioning system in an automobile are as follows:

expansion valve, condenser, evaporator and receiver drier are all components of the compressor system. In the engine compartment, a belt drives the compressor.

Four of the five components are positioned in the passenger compartment.

Gases are compressed to high pressure as they pass through the compressor at low pressure. Once the high-pressure gas reaches the condenser (placed next to the radiator), it is condensed. The refrigerant becomes a liquid when heated by the radiator.

Afterward, the refrigerant returns to gas form in the expansion valve. As a result of this state shift, the liquid is now able to absorb a significant amount of heat from the cabin air. It then enters the evaporator, which is situated in the dashboard.

More heat from the air causes the gas to become liquid again. The receiver drier dries the liquid refrigerant before returning it to the compressor, where the cycle is repeated.

Why Does My Car Air Conditioning Unit Not Work?

There are a few possible explanations for a malfunctioning air conditioner in your vehicle. The most typical cause is a failure of the AC compressor to operate. Problems with the compressor clutch or an electrical system could be to blame, as could a shortage of refrigerant.

One of the most prevalent issues is the AC fan not working. A blown fuse, a bad fan motor, or a clogged air filter are all possibilities for why this is happening. Finally, it’s possible that the AC condenser is obstructed by debris or ice.

Take your car to a repair if the AC unit isn’t working. Depending on the extent of the damage, a simple patch may be all that’s needed. When it comes to the summer months, it’s extremely crucial to get the problem corrected as soon as possible.

What’s An AC Clutch?

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Compressors can be engaged and disengaged from the engine using the AC compressor clutch. The compressor will kick on and begin compressing the refrigerant as soon as the clutch is engaged. The compressor will not run if the clutch is not engaged.

An electromagnetic coil often governs the AC compressor clutch. Flowing current creates a magnetic field, which pulls the clutch plate toward the pulley. The compressor is activated by pressing this button.

The clutch plate is pulled away from the pulley by the spring when the coil is not receiving any current. The compressor is now off.

Can My AC Compressor Clutch Get Stuck?

Unstable AC compressor clutches are not unknown. A lack of lubrication or an issue with the electromagnetic coil is the most common reason of this. When the clutch is stuck, the pulley will not be disengaged, resulting in the compressor running continuously.

What Does Manual AC Compressor Clutch Mean?

A clutch that may be engaged and disengaged manually, such as an AC compressor clutch, does not require the usage of electricity. Even if there is no power flowing to the coil, the clutch can still be engaged by the driver.

AC compressor clutches come in two varieties.

Activate and then let go. Having a lever or knob that may be used to engage the clutch when the vehicle is not in use is a good idea. In order to release the clutch without losing power, a lever or knob is provided on release clutches.

How Can I Be Sure My AC Has A Problem With The Coil?

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The coil is the first thing to check if your AC compressor’s clutch does not engage. You’ll need a multimeter for this. When using a multimeter to measure resistance, connect the leads to the terminals on the coil’s windings. In this case, the coil is almost certainly faulty.

An ohmmeter can also be used to check the coil. You can detect if there is a connection between the coil’s two terminals if this works. In this case, the coil is almost certainly faulty.

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How Do I Test The AC Compressor Clutch Relay?

Using a voltmeter or a test light is the best technique to check a relay. To begin, locate the relay in question and determine which terminal is wired to the power source.. After that, start the engine and use a voltmeter or a test light to measure the voltage at this connector.

This means the relay is working if the voltage is there. It is quite likely that the relay is broken.

How Do I Test The AC Compressor Clutch Switch?

In order to test a switch, a multimeter is required. Using a multimeter, connect the leads to the terminals of the switch and measure the continuity of the wires. The switch is functioning properly if there is a continuous signal. If this is not the case, the switch is likely faulty.

Why Would I Manually Engage An AC Compressor Clutch?

The AC compressor clutch may need to be manually engaged for a variety of reasons. The electrical system is the most prevalent culprit. In some cases, this may be due to a broken fuse, a damaged switch or a bad wire in the electrical system.

You may also need to manually activate the AC compressor’s clutch if the compressor itself is not operating. Piston rings, seals, or bearings may be to blame for this issue.

Finally, if the air conditioning unit is low on refrigerant, you may need to manually engage the AC compressor clutch.

How Can I Manually Engage My AC Clutch?

You may need to manually engage the AC compressor clutch if your car’s AC unit is not operating and you cannot detect a fault with the electrical system. If all previous troubleshooting methods have failed, this process should be used as a last option.

Before anything else, find the AC compressor’s clutch. It’ll be near the compressor in the engine compartment. A cover or shroud may need to be removed to access it.

The clutch oil cable must be disconnected once the AC compressor has been discovered. When you try to engage the clutch, the compressor will not be damaged because of this.

Once you’ve removed the clutch oil cable, double-check that you have enough refrigerant in the system. It’s also a good time to top off the AC if you’re running low.

Make sure your compressor is lubricated and free of leaks, as well. After that, you’ll have to figure out how to power the coil. The coil can be connected directly to the battery or a jumper wire can be used.

In order to activate the compressor, you’ll need to supply it with electricity. It’s possible that the coil or other portions of the AC system are faulty.

If you turn on the AC compressor without refrigerant, you risk damaging it. Refrigerant levels must be checked before manually starting the compressor!

If you’ve removed any covers or shrouds, reinstall them once the clutch is engaged. Start the car by reconnecting the negative battery cable. Hopefully, the AC compressor is now working as it should.

Taking your car to a mechanic for help if you run into any issues during this process.


How Can I Check The Level Of Refrigerant?

Using a pressure gauge is the best technique to check the refrigerant level. Most auto parts stores have these, or you can order them online by visiting the link provided below.

The internal pressure of the refrigerant can be measured using a pressure gauge attached to the AC system. Gauges come in two varieties. high and low pressure. Pressure in a sealed system is measured by a low pressure gauge; pressure in an open system is measured by a high pressure gauge.

The sort of gauge you have will determine how well you can use your pressure gauge. Owners manuals or a mechanic can help you if you’re not sure. Once you’ve found the Schrader valve, you’re good to go. The gauge will be attached here.

Once the gauge is installed, start the engine and switch on the air conditioning. If the compressor isn’t running, it should be. Gauge readings can then be taken. Adding refrigerant is necessary if pressure is low. Consult your vehicle’s owner’s handbook or a mechanic for more information.

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Where Is The Schrader Valve Located?

Most air conditioners have a Schrader valve near the compressor. It may be encased in a shroud or hose that must be removed to get to it. If you can’t find it, consult your car’s owner’s manual or bring it to a mechanic.


Only use the AC compressor clutch manually if you have no other choice.. Make sure there are no leaks in the system and that you have enough refrigerant and oil.

Applying too much electricity to the coil can destroy the compressor, so exercise extreme caution. Take your car to a mechanic if you’re unsure about this technique. Thank you for reading!