FAW Air-Conditioning Compressor: A Critical Guide to Its 3 Components

Welcome to this critical technical guide on the FAW Air-Conditioning Compressor (Part No. 8103020-36D). This component is the heart of the Heating, Ventilation, and Air Conditioning (HVAC) system for the FAW Jiefang CA4251P66K24T1A3E5 6×4 diesel semi-trailer tractor.

The function of the FAW Air-Conditioning Compressor is to provide driver comfort and safety (defrosting) by pumping refrigerant through the A/C loop. It is a high-load, belt-driven pump that converts low-pressure refrigerant gas into a high-pressure, high-temperature gas.

This in-depth guide is an essential resource for professional technicians, fleet managers, and parts specialists. We will deconstruct the entire FAW Air-Conditioning Compressor assembly and its 3 serviceable mounting components, including the main compressor unit and its critical fasteners, to ensure precise service and diagnostics.

Core Component: The A/C Compressor Assembly (8103020-36D)

The main component is the ‘A/C Compressor Assembly’ (8103020-36D). This is the complete FAW Air-Conditioning Compressor unit. This is a heavy-duty, belt-driven pump that is mounted to a bracket on the engine. It is powered by the engine’s main serpentine belt.

The function of the FAW Air-Conditioning Compressor is to serve as the “heart” of the A/C loop. It draws in low-pressure, low-temperature refrigerant gas (like R134a or R1234yf) from the evaporator (the component inside the truck’s dashboard). It then compresses this gas, which dramatically increases its pressure and temperature. This high-pressure, hot gas is then pushed out of the compressor and into the condenser (the component in front of the radiator).

A heavy-duty FAW Air-Conditioning Compressor like this one is typically a “swash plate” or “wobble plate” design. This means a set of pistons (usually 5 or 7) are housed inside a cylinder block. The engine’s pulley spins an angled plate (the swash plate), which pushes these pistons back and forth, sucking in the gas and then forcing it out at high pressure. This design is robust and capable of moving a large volume of refrigerant. The FAW Air-Conditioning Compressor is a precision-engineered, high-load component.

Internal Logic: The Electromagnetic Clutch

A key sub-component of the FAW Air-Conditioning Compressor (8103020-36D) is its electromagnetic clutch. The compressor’s pulley is always spinning, as it is connected to the engine’s main serpentine belt. However, the compressor itself should only be pumping when the driver requests A/C.

The clutch is the switch that engages and disengages the pulley from the compressor’s internal swash plate. When the driver presses the A/C button, a 24-volt signal is sent to an electromagnet located inside the pulley assembly. This magnet creates a strong magnetic field.

This magnetic field pulls a “clutch plate,” which is mounted to the compressor’s input shaft, hard against the spinning pulley. The friction between the plate and the pulley “locks” them together. This transfers the engine’s rotation to the compressor’s internal pistons, and the pumping begins. The loud “click” heard when the A/C is turned on is the sound of this clutch plate engaging.

This clutch is a primary failure point for any FAW Air-Conditioning Compressor. The clutch can wear out and begin to slip, or the electromagnet coil can fail (an “open circuit”). This is why a common “no A/C” diagnostic is to check if the 24V signal is reaching the FAW Air-Conditioning Compressor, and if the clutch is engaging when it does.

Variable Displacement vs. Clutch Cycling

Many modern systems, including this FAW Air-Conditioning Compressor, may be of a “variable displacement” design. This is a more advanced logic than simple “clutch cycling.”

In an older “clutch cycling” system, the compressor is either 100% ON or 100% OFF. The clutch cycles on and off every few minutes to maintain the correct temperature, which can be inefficient and cause a noticeable “jerk” as the engine load changes.

A variable displacement FAW Air-Conditioning Compressor is much smarter. The clutch engages *once* and stays engaged. The compressor’s output is then controlled by an internal electronic solenoid that changes the *angle* of the swash plate. A steep angle causes a long piston stroke, providing 100% output on a hot day. A shallow angle causes a very short stroke, providing perhaps only 10% output to simply maintain the temperature.

This variable logic makes the FAW Air-Conditioning Compressor far more efficient, as it only draws as much power from the engine as is absolutely necessary. This saves fuel and provides a much more stable and comfortable cabin temperature. A failure of this internal control solenoid is another common diagnostic point for the FAW Air-Conditioning Compressor.

The Mounting Hardware System (3701327-36D & Q32010)

The parts list for the FAW Air-Conditioning Compressor assembly is simple and focuses on the mounting hardware. The ‘Bolt – for fastening AC generator’ (3701327-36D) is a classic example of “parts-bin engineering.” Although the name refers to the AC Generator (alternator), this part is a high-tensile stud that is also used for mounting the FAW Air-Conditioning Compressor.

This system uses two of these studs (3701327-36D). These studs are threaded into the main A/C compressor mounting bracket, which is bolted to the engine. The body of the FAW Air-Conditioning Compressor is then slid onto these two studs.

The ‘Hex flange nut’ (Q32010), of which there are two, is then used to secure the FAW Air-Conditioning Compressor to the studs. This “stud and nut” system is superior to a simple bolt, as it puts less wear on the threads in the main (and often aluminum) engine bracket. The “flange” on the nut is critical; it’s an integrated washer that spreads the clamping force, preventing the nut from cracking the compressor’s aluminum mounting ears or vibrating loose. This robust mounting is essential for keeping the FAW Air-Conditioning Compressor perfectly aligned with the serpentine belt.

FAW Air-Conditioning Compressor Parts List

The following table provides the complete, detailed breakdown of all 3 components identified in the ‘Air-Conditioning Compressor’ diagram for the FAW CA4251P66K24T1A3E5 tractor. A replacement FAW Air-Conditioning Compressor is a key part of HVAC service.

Technical Specifications and Assembly Context

The specifications for the FAW Air-Conditioning Compressor are defined by its function as a high-pressure refrigerant pump. The entire FAW Air-Conditioning Compressor is a key component for driver comfort and safety (defrosting).