The part is a comprehensive component kit for the climate control system in the HOWO MAX 4X2 tractor cab. This YG1671821000/2 set includes every essential internal part of the HVAC unit, from speed control modules and actuators to heating and evaporator cores, sensors, wiring harness, and blower assembly – all engineered to the original Hubei American standard specifications. When you choose authentic Howo Parts, this YG1671821000/2 guarantees OE fitment, seamless integration, and reliable climate control performance. Below are detailed descriptions of every component included with this YG1671821000/2 kit.
The speed control module is the electronic regulator that governs the blower motor speed within The part system. This module uses pulse-width modulation to precisely adjust motor voltage, delivering smooth and silent fan operation across all speed settings. The module includes over-temperature protection and is designed to handle the high current demands of the HVAC blower.
The fresh air door actuator is an electric motor that controls the recirculation/fresh air door within The part system. It moves the door to allow outside air into the cabin or to recirculate internal air, based on driver selection. This actuator includes a feedback potentiometer for precise position monitoring, ensuring accurate operation of the ventilation modes.
The cold and warm air door actuator (temperature blend actuator) adjusts the blend door that mixes hot and cold air to achieve the desired cabin temperature. This YG1671821000/2 actuator responds to signals from the automatic climate control panel, precisely positioning the blend door to deliver the correct air temperature, ensuring occupant comfort.
The pattern executor (mode actuator) operates the mode doors that direct airflow to the dashboard vents, floor, or windshield defrost outlets. This YG1671821000/2 actuator is a stepper motor with an integrated position sensor, enabling precise mode selection and reliable distribution of conditioned air to the desired cabin zones.
The heating core assembly is the heater core that transfers heat from the engine coolant to the cabin air. This YG1671821000/2 component is a fin-and-tube aluminium heat exchanger, offering high thermal efficiency and resistance to coolant temperatures up to 120°C. It is pressure-tested to ensure leak-free operation and is a key element of the heating function.
The evaporator core assembly is the cooling element where refrigerant evaporates and absorbs heat from the cabin air. This YG1671821000/2 core is made from aluminium with a labyrinth fin design that maximises surface area for efficient heat exchange. It is coated for corrosion resistance and is crucial for the air conditioning performance of the system.
The outside temperature sensor is a thermistor that measures the ambient temperature outside the cab. This YG1671821000/2 sensor provides input to the automatic climate control system, helping the HVAC unit determine the required cooling or heating capacity. It is mounted externally and protected from the elements for accurate readings.
The unit wiring harness is the complete electrical interconnection assembly for The part system. It uses high-temperature XLPE insulated wires with sealed connectors, pre-formed to match the exact routing of the HVAC unit. The harness simplifies installation by providing all necessary connections between actuators, sensors, and the blower motor.
The indoor temperature sensor is located inside the cab, typically near the control panel, and measures the cabin air temperature. This YG1671821000/2 sensor is a critical feedback element for the automatic temperature control, allowing the system to maintain the set temperature accurately. It uses an NTC thermistor for reliable sensing.
The blower assembly is the fan unit that draws air through The part HVAC module and delivers it into the cabin. This assembly includes a high-efficiency centrifugal fan wheel driven by a 24V DC motor, offering high airflow with low noise. The blower is dynamically balanced for smooth operation, ensuring consistent air distribution.
The evaporator temperature sensor is a thermistor mounted on the evaporator core fins that monitors the core surface temperature. This YG1671821000/2 sensor is used to prevent the evaporator from freezing by cycling the compressor off when the temperature drops below a safe threshold (typically 3°C). It protects the system and ensures efficient operation.
YG1671821000/2 – genuine HOWO complete HVAC module component kit for MAX 4X2
This YG1671821000/2 kit includes every actuator, core, sensor, harness, and blower needed for a full HVAC rebuild. With YG1671821000/2, you have all the internal parts to restore the climate control system to factory specification.
All components of The part are manufactured to the Hubei American standard, ensuring compatibility with the original automatic climate control system. The part guarantees precise actuator positioning and accurate sensor readings.
The heating and evaporator cores in The part are designed for maximum thermal efficiency, providing rapid cabin heating and cooling. The part core assemblies use aluminium construction for lightweight, corrosion-resistant performance.
The unit wiring harness in this YG1671821000/2 kit is pre-formed and colour-coded, matching the original connector layout. Installing The part harness eliminates guesswork and reduces installation time significantly.
The part components form a complete and integrated climate control system. The speed control module regulates the blower motor speed to deliver the desired airflow. The fresh air door actuator, cold/warm air door actuator, and pattern executor work together to control air source, temperature, and distribution. The heating core and evaporator core provide the thermal exchange necessary for heating and cooling. The outside, indoor,
and evaporator temperature sensors feed real-time data to the control unit, which adjusts actuator positions and compressor operation to maintain the set temperature. The unit wiring harness interconnects all these components, ensuring reliable communication and power distribution. A properly functioning YG1671821000/2 system ensures that the driver and passengers enjoy consistent,
comfortable cabin conditions regardless of outside weather. Any failure in The part components can lead to poor heating, insufficient cooling, or incorrect airflow distribution, underscoring the importance of using genuine parts for replacement.
Each component of The part kit is precision-engineered to the highest standards. The speed control module is rated for 24V operation and can handle up to 15A of current, with built-in short-circuit protection. The actuators are stepper motors with integrated gears and position feedback, offering 0.5° positioning accuracy. The heating core features 18 cooling fins per inch for optimal heat transfer,
while the evaporator core has a 12-row parallel flow design. All sensors are NTC thermistors with a tolerance of ±1°C. The wiring harness uses 0.5mm² copper conductors with cross-linked polyethylene insulation, providing excellent heat resistance and mechanical strength.
Each YG1671821000/2 component is tested for thermal shock, vibration, and humidity resistance, ensuring durability in the demanding truck environment. The part kit is a complete solution for HVAC system overhaul, eliminating the need to source individual parts from different suppliers.
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 each actuator and sensor. Clean the housing and mounting brackets. Install the new heating core and evaporator core into the housing. Mount the speed control module and the three actuators (fresh air, blend, mode) to their respective shafts, ensuring correct alignment.
Connect the unit wiring harness to all actuators and sensors. Install the blower assembly and secure all components with the original fasteners. Reinstall The part assembly into the dashboard, reconnect the refrigerant lines and coolant hoses.
Recharge the system with the specified amount of R-134a refrigerant. Reconnect the battery and test The part system by cycling through all modes and temperature settings. Verify that the actuators move correctly and that temperature changes are smooth. Check for any diagnostic trouble codes using the climate control panel. The part installation is now complete.
If the blower does not operate, check the speed control module and the blower motor connector. A faulty fresh air door actuator may prevent recirculation; listen for clicking or binding. If the temperature does not vary, the cold/warm air door actuator may be stuck; verify its movement with a diagnostic tool.
If air distribution fails, the pattern executor gear may be broken. Sensor failures can cause erratic operation; test resistance values with a multimeter. A damaged wiring harness can cause intermittent faults; inspect for chafing. Always use genuine YG1671821000/2 components for repairs to ensure proper function and compatibility.
Inspect The part system annually or every 40,000 km. Replace the cabin air filter (not included) to maintain airflow. Check actuator linkages for smooth movement. Clean the evaporator core fins with compressed air.
Test sensor readings with a scanner and compare with ambient temperatures. Lubricate actuator gears with silicone grease if they become stiff. If the blower develops noise, inspect for debris in the housing. Regular maintenance of The part components ensures long-lasting, trouble-free operation and consistent cabin comfort.
This YG1671821000/2 kit is specifically designed for the HOWO MAX 4X2 tractor with the NX cab and the Hubei American standard HVAC system. It is compatible with all production years from 2018 onward. The part is also suitable for SITRAK C7H and HOWO T7H models using the same HVAC architecture. It is not compatible with manual control systems or older non-standard actuators. Always verify your vehicle’s HVAC configuration before ordering The part.
Aftermarket YG1671821000/2 components often use lower-quality plastics and metals that fail prematurely. Generic sensors may have incorrect resistance curves, causing inaccurate temperature control. Non-genuine harnesses may lack proper insulation, leading to short circuits. A failed YG1671821000/2 system can leave the driver without heat or air conditioning,
significantly reducing comfort and safety. Genuine HOWO YG1671821000/2 components are manufactured to SINOTRUK’s exacting standards, using durable materials, precise calibration, and reliable connectors. The small additional cost of a genuine YG1671821000/2 is far outweighed by the comfort, safety, and reliability it provides to the driver and vehicle.
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