Compressor AC clutch not engaging

Compressor AC clutch not engaging - Air conditioning compressors are equipped with an electromagnetic clutch as part of the compressor pulley assembly in most modern vehicles. The compressor clutch is designed to engage the compressor pulley to the compressor shaft when the clutch coil is energized by electricity. An electronic circuit controls the Air Conditioning (AC) system to energize the ac clutch coil. It can do by the ECM and a relay.

The compressor ac clutch's role is to transmit power from the engine to the compressor and provides a mechanism of engaging and disengaging the refrigeration system from engine operation. The ac clutch is driven by one or more of the drive belts fitted to the engine.

When the ac clutch is engaged, the engine power is transferred from the pulley to the compressor shaft through the ac clutch drive plate. The compressor shaft doesn't rotate when the ac clutch is not engaged, and the pulley rotates free until re-engaged.

As the ac clutch is engaged, it creates refrigerant flow within the system. It makes your car's air conditioner cool the air temperature inside your vehicle.

In several cases, especially when your car's AC system doesn't work and the temperature won't be cooling down. We can found that the compressor ac clutch not working and it looks not engage. Why is the compressor ac clutch not engaging? In this article, we will inform some of the causes of the compressor ac clutch not engaging.

1. Open circuit in the AC compressor clutch system

As we mentioned before, the AC compressor clutch system is controlled by an electronic circuit. It should work in a closed circuit. If the AC system wiring circuit has an open circuit, the AC compressor clutch will not engage. Also, your car's Air conditioner won't work normally. Here are the most common causes for the compressor ac clutch not engaging.

Blown fuse AC compressor clutch

AC compressor clutch using fuse to secure the system from overload current capacity. If any overload current flows through this fuse, then the fuse will break up and stop the current flow. When the ac clutch fuse breaks up, the ac clutch engages then stops at that time. We can see the ac clutch not spinning anymore. As a result, the AC compressor clutch is not energized and makes your car AC system won't cool down the air temperature.

Bad AC compressor relay's

Besides using a fuse, the ac clutch compressor also uses a relay. The relay protects the AC switch module in the dash panel from a large electric current. In some cases, the relay's coil breaks up and stops the electric current flowing through the relay. As a result, the electric current from the battery to the AC compressor clutch coil doesn't flow, so the AC clutch wont engage.

Bad ac clutch coil

A bad ac clutch coil is also can make your compressor ac clutch not engaging. In most cases, a bad ac clutch coil means that the coil inside breaks up. When the ac clutch coil is broken up, the electric current won't flow so that the coil won't generate an electromagnetic field. It also makes the AC clutch won't engage.

Bad AC switch module

A bad AC switch module can make your compressor ac clutch not engaging. This module is a switch we often use to turn on the AC system from the vehicle dashboard. In several cases, the AC switch module can have a malfunction or error. This malfunctioning AC switch module will disrupt the electric current flow to the ac clutch coil. As it happens, the ac clutch wont engages anymore.

Poor grounding

The last open circuit in the AC compressor clutch that makes it won't engage is from the poor ground. We can see the cable ground near the AC compressor. Sometimes, it gets rusted and breaks up. The poor ground can interrupt the electric flow and decreasing the magnetic power so the clutch won't engage.

2. Bad refrigerant pressure switch

The second common cause for the compressor ac clutch not engaging is the bad refrigerant pressure switch. The AC system needs refrigerant to convert the heat into cool air. As the AC compressors works, the refrigerant will be pressurized.

The AC systems use pressure switches called refrigerant pressure switches to control the refrigerant pressure. In most vehicles, we can see several refrigerant pressure switches. There are high-pressure switches and low-pressure switches. Commonly, the AC compressor clutch is connected to the low-pressure switch.

If the low-pressure switch is going bad, then the electric current won't flow to the ground. It makes the AC compressor relay won't work. As a result, the clutch is not engaged.

3. Poor Refrigerant Volume

The last common cause for compressor ac clutch not engaging is poor refrigerant volume. AC system needs exact refrigerant volume to make it work. Too low or too high can be badly impacted on the ac system.

This case (the AC compressor clutch is not engaging) is commonly caused by poor refrigerant volume. Low refrigerant volume can impact the low-pressure switch. As we mentioned before, a low-pressure switch works will operate the ac compressor relay.

If there isn't enough pressure, then the switch won't work. As a result, the AC compressor clutch is not engaging.