The part is the heart of the climate control system in the HOWO MAX 4X2 tractor cab, integrating all key HVAC components into a single, serviceable unit. This genuine HOWO Air conditioner assembly kit includes the speed regulation module, fresh air door actuator, cold/warm air door actuator, mode actuator, warm air core, evaporator core, outside temperature sensor, unit wiring harness, indoor temperature sensor, blower assembly, and evaporator temperature sensor – all precision-engineered to deliver reliable cooling, heating, and ventilation. When you choose authentic Howo Parts, this Air conditioner assembly guarantees OE fitment, efficient performance, and long-term durability. Below are detailed descriptions of every component included with this Air conditioner assembly.
The speed regulation module is the electronic controller that adjusts the blower motor speed based on the fan switch setting. This Air conditioner assembly component uses pulse-width modulation to precisely control motor voltage, ensuring smooth and quiet operation. The module is built with high-current MOSFETs and includes thermal protection to prevent overheating. It is a critical part of The part, directly affecting cabin airflow and comfort.
The fresh air door actuator is an electric motor that operates the recirculation/fresh air door within The part. This actuator moves the door to allow outside air into the cabin or to recirculate internal air, depending on the driver’s selection. The actuator is fitted with a feedback potentiometer that tells the control panel the door’s position, ensuring accurate operation. This Air conditioner assembly component is essential for maintaining cabin air quality and reducing humidity.
The cold and warm air door actuator (also called the temperature blend door actuator) controls the blend door that mixes hot and cold air to achieve the desired cabin temperature. This Air conditioner assembly actuator is a key component in the automatic temperature control system, responding to signals from the control panel to precisely position the blend door. It ensures that The part delivers the correct air temperature to the cabin, improving driver comfort.
The mode actuator operates the mode doors that direct airflow to the dashboard vents, floor, or windshield defrost outlets. This Air conditioner assembly actuator is responsible for selecting the desired air distribution mode, such as face, feet, or defrost. It is a stepper motor driven component with an integrated position sensor, ensuring precise mode selection and reliable performance of The part.
The warm air core assembly is the heater core that transfers heat from the engine coolant to the cabin air. This Air conditioner assembly component consists of a fin-and-tube heat exchanger made from aluminium, offering high heat transfer efficiency. The warm air core is an integral part of The part, providing the heat source for the heating function. It is designed to withstand coolant temperatures up to 120°C and is pressure-tested for reliability.
The evaporator core assembly is the cooling element of The part, where the refrigerant evaporates and absorbs heat from the cabin air. This Air conditioner assembly component is made from aluminium with a corrosion-resistant coating and features a labyrinth design to maximise surface area and heat exchange efficiency. The evaporator core is a critical part of The part, directly affecting cooling performance and dehumidification.
The outside temperature sensor is a thermistor that measures the ambient air temperature outside the cab. This Air conditioner assembly sensor provides input to the automatic climate control system, helping The part determine the required cooling or heating capacity. The sensor is mounted on the exterior of the vehicle and is protected from the elements. Accurate readings from this sensor are essential for the proper functioning of The part.
The unit wiring harness is the complete electrical wiring assembly that interconnects all actuators, sensors, and the blower motor within The part. This harness uses automotive-grade cross-linked polyethylene (XLPE) insulated wires, rated for 105°C, and features sealed connectors that prevent moisture ingress. The harness is pre-formed to match the exact routing of The part, simplifying installation and eliminating the risk of wiring errors.
The indoor temperature sensor is located inside the cab, typically near the control panel, and measures the cabin air temperature. This Air conditioner assembly sensor is a critical input for the automatic temperature control system, allowing The part to maintain the set temperature accurately. The sensor uses a negative temperature coefficient (NTC) thermistor and is housed in a protective grill to prevent damage.
The blower assembly is the fan unit that draws air through The part and pushes it into the cabin. This assembly includes a high-efficiency centrifugal fan wheel driven by a 24V DC motor, capable of delivering high airflow at low noise levels. The blower is dynamically balanced for smooth operation and is a key component of The part, ensuring that cooled or heated air reaches all parts of the cab effectively.
The evaporator temperature sensor is a thermistor mounted on the evaporator core fins that monitors the surface temperature of the evaporator. This Air conditioner assembly sensor is used to prevent the evaporator from freezing by cycling the compressor off when the temperature drops below a set threshold (typically 3°C). It ensures The part operates efficiently and protects the evaporator from ice buildup, which could restrict airflow.
Air conditioner assembly – genuine HOWO complete HVAC module and component set for MAX 4X2
This Air conditioner assembly kit provides all the internal components needed to rebuild or replace the HVAC unit, from actuators and sensors to cores and the blower. No extra parts are required to restore full climate control functionality.
All actuators and sensors in this Air conditioner assembly are manufactured to Hubei American standard specifications, ensuring compatibility with the original control panel and precise operation of the blend doors and mode functions.
The warm air core and evaporator core included in this Air conditioner assembly are designed for maximum heat transfer efficiency, providing rapid cabin heating and cooling. The aluminium construction offers lightweight and corrosion-resistant performance.
The part includes the complete unit wiring harness, pre-terminated and routed to match the exact connector locations of the HVAC unit. This simplifies installation and eliminates the risk of wiring mistakes.
The part is a modular system designed for serviceability. The speed regulation module uses high-frequency PWM to minimise motor noise. The three actuators (fresh air, blend, mode) are all stepper-motor driven, providing precise positioning and self-diagnostic feedback. The warm air core is brazed aluminium with a 16-row design, and the evaporator core features parallel flow tubes for enhanced heat transfer.
The sensors are NTC thermistors with ±1°C accuracy. The blower assembly uses a 24V motor with a balanced centrifugal impeller, delivering airflow up to 400 m³/h. The wiring harness uses colour-coded wires with printed labels at each connector, facilitating identification during assembly.
All components are tested for vibration and thermal shock resistance, ensuring they withstand the harsh conditions of heavy-duty trucking. The part is designed to fit the HOWO MAX 4X2 NX cab and is fully compatible with the automatic climate control system.
Before installing The part, discharge the refrigerant and disconnect the battery. Remove the dashboard trim and the old HVAC unit. Carefully disassemble the old unit, noting the positions of all actuators and sensors. Clean the mounting brackets. Install the new warm air core and evaporator core into the housing. Mount the actuators to their respective door shafts, ensuring correct alignment. Connect the wiring harness to the actuators and sensors.
Install the blower assembly and the speed regulation module. Secure all components with the original fasteners. Reinstall The part into the dashboard, reconnect the refrigerant lines and coolant hoses. Recharge the system with R-134a refrigerant. Reconnect the battery and test The part by operating all modes and temperature settings. Check for proper airflow and temperature changes. The part installation is now complete.
If the blower does not operate, check the speed regulation module and the blower motor connector. A faulty fresh air door actuator may cause the recirculation function to fail; listen for clicking sounds from the actuator. If the temperature does not vary correctly, the cold/warm air door actuator may be stuck; test its movement with a diagnostic tool.
If the air distribution does not change, the mode actuator may have a broken gear. Sensor failures can cause The part to operate erratically; use a multimeter to check resistance values. A damaged wiring harness can cause intermittent faults; inspect for chafing or broken wires. Always use genuine Air conditioner assembly components for repairs to maintain correct operation.
The part should be inspected annually or every 40,000 km. Replace the cabin air filter (not included) to ensure optimal airflow and air quality. Check the actuator linkages for smooth movement. Clean the evaporator core fins with a soft brush and compressed air.
Test the sensor readings with a diagnostic scanner and compare with ambient conditions. Lubricate the actuator gear trains with silicone grease if they become stiff. If The part develops unusual noises, inspect the blower motor and impeller for debris. Regular maintenance of The part extends its service life and ensures consistent cabin comfort.
This Air conditioner assembly kit is specifically designed for the HOWO MAX 4X2 tractor with the NX cab interior and the Hubei American standard HVAC system. It is compatible with all production years from 2018 onward. The actuators and sensors are matched to the automatic climate control panel.
This Air conditioner assembly is also suitable for SITRAK C7H and HOWO T7H models that use the same HVAC architecture. It is not compatible with older manual control systems or with cabs that use different actuator standards. Always verify your vehicle’s HVAC configuration before ordering.
Aftermarket Air conditioner assembly components often use inferior plastics and metals that fail under stress, leading to door jams or broken gears. Generic sensors may have incorrect resistance curves, causing inaccurate temperature readings and poor climate control. Non-genuine harnesses may have inadequate insulation,
leading to short circuits and fire risks. A failed Air conditioner assembly can leave the driver without heat in winter or without cooling in summer, significantly reducing comfort and driver alertness.
Genuine HOWO Air conditioner assembly components are manufactured to SINOTRUK’s exacting standards, using durable materials, precise calibration, and reliable connectors. The small additional cost of a genuine Air conditioner assembly is far outweighed by the comfort, safety, and reliability it provides to the driver and vehicle.
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