Catalog

GREAT WALL 3747100K00 MOTOR SUB-ASSY

Product Specifications

Product quality
OEM Equivalent Grade
starstarstar
Wholesale price USD $1.31
Wholesale price CNY ¥9
bolt MOQ (Minimal order)
50 pcs
local_shipping Production time
5-7 days
package_2 Shipping Weight: 0.03 kg
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GREAT WALL 3747100K00
Overview & Operating Principle
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The MOTOR SUB-ASSY is a permanent-magnet DC motor or electronically commutated brushless motor mounted inside the HVAC housing under the dashboard that drives a centrifugal squirrel-cage fan wheel to draw air through the cabin air filter and heater core or evaporator matrix and force it through the selected distribution ducts into the passenger compartment. The motor shaft is directly coupled to the fan wheel without a gearbox — impeller speed is proportional to motor speed, and airflow volume is proportional to impeller speed. On conventional systems the motor speed is controlled by a blower resistor pack or speed control module that reduces the supply voltage in discrete steps to provide the low, medium, and high speed settings selected on the HVAC panel. On automatic climate control systems the motor receives a continuous PWM signal from the climate control module that varies motor speed infinitely between minimum and maximum to maintain the cabin temperature target, with a dedicated power transistor module or HVAC control unit managing the motor drive circuit. The motor and fan wheel are supplied as an integrated sub-assembly on most applications — the fan wheel is retained on the motor shaft by a circlip or press-fit hub and is balanced as a matched pair at the factory; replacing the motor alone without the fan wheel is not recommended as the replacement motor's dynamic balance cannot be verified with a used fan wheel.

This unit — GREAT WALL 3747100K00 — is manufactured to OEM-equivalent specifications: motor rated voltage and current draw at each speed step, shaft diameter and length, fan wheel outer diameter and blade geometry, overall assembly mounting flange dimensions and bolt pattern, connector pinout, and rotation direction are matched to the original part. Supplied as a direct replacement for standard fitment. Available wholesale from 1.31 USD, MOQ 50 pcs, production lead time 5-7 days.

Blower motors fail through carbon brush and commutator wear on brushed DC motors producing progressively increasing resistance and eventually complete open-circuit failure, bearing wear causing the shaft to run off-centre and contact the motor housing producing noise and vibration, and winding insulation degradation from long-term heat exposure in the high-temperature underdashboard environment. Foreign object ingestion — leaves, rodent nesting material, or broken fan wheel fragments — is a secondary failure cause that damages both the fan wheel and the motor bearing simultaneously. Before replacing the motor, confirm the failure is not caused by a failed blower resistor pack or PWM control module by verifying full battery voltage reaches the motor connector on the highest speed setting.

Symptoms & Diagnostics
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No airflow from any vent at any blower speed setting — confirm 12V supply reaches the motor connector at the highest speed setting with a multimeter; if voltage is present and the motor does not run, the motor winding has failed; if no voltage is present at any speed, the blower fuse, relay, or speed control module has failed and the motor itself may be serviceable.
Blower operates on high speed only, with no airflow on lower speed settings — the blower resistor pack that reduces motor voltage for low and medium speeds has failed open-circuit on all resistance stages; the motor bypasses the resistor on the highest speed setting which connects battery voltage directly, confirming the motor is serviceable and only the resistor requires replacement.
Loud rattling, scraping, or grinding noise from the blower area that increases with blower speed — foreign object ingestion, a broken fan wheel blade, or a failed motor bearing allowing the fan wheel to contact the housing; switch off the blower immediately to prevent further damage and inspect the fan wheel and housing for debris or blade damage before diagnosing the motor bearing.
Burning electrical smell from the dashboard vents when the blower is running — motor winding insulation breakdown from overheating or a partial short circuit in the motor winding; switch off immediately as a motor winding fire is possible under sustained operation with a shorted winding; do not restart until the motor has been replaced.
Blower motor that works correctly when cold but stops after 10–15 minutes of operation — a motor with degraded winding insulation that shorts when the winding temperature rises, or a motor bearing that binds when thermally expanded; the thermal failure pattern points to internal motor failure rather than the external speed control circuit.
Vibration felt through the dashboard and vents at all blower speeds — a fan wheel that has lost one or more balance weights, has accumulated asymmetric debris on its blades, or has a cracked blade causing mass imbalance; clean the fan wheel before replacing the motor assembly as blade debris accumulation is a frequent cause of vibration that does not require motor replacement.
Logistics & Customs
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International HS Code
8414.59
EAEU Customs Code (TN VED)
8414 59 200 0
Typical Net Weight
0.03 kg
Country of Manufacture
China
Standard MOQ
50 pcs
Production Lead Time
5-7 days
Always verify the exact 8-digit or 10-digit subheading with your customs broker for the destination country, as tariff schedules and duty rates vary by jurisdiction.
Installation Tips
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  1. Confirm the blower motor is the failed component before beginning dashboard disassembly — apply 12V and ground directly to the motor connector terminals using a test lead; a motor that runs normally under direct power but not under HVAC system control has a failed resistor pack, relay, or control module rather than a failed motor; direct-power testing saves the full dashboard access labour on a serviceable motor.
  2. Disconnect the negative battery terminal before removing any underdashboard components — the blower motor wiring runs adjacent to airbag system wiring and SRS connectors in most vehicles; working in the underdashboard area with live circuits risks accidental airbag deployment; always disconnect the battery and wait the manufacturer's specified SRS discharge time before beginning work.
  3. Access the blower motor housing — typically located on the passenger side under the glovebox or behind the lower dashboard trim panel; on most vehicles the motor assembly is retained by three screws on a flanged mounting ring and is accessible without removing the complete HVAC box; photograph the wiring routing and any harness clip positions before disconnecting to confirm correct reassembly.
  4. Remove any foreign object debris from the blower housing interior before fitting the new motor assembly — use a vacuum and a torch to inspect and clean the housing cavity thoroughly; leaf fragments, rodent nesting material, or broken blade pieces left in the housing will be immediately ingested by the new fan wheel on first operation, destroying it within seconds.
  5. Confirm the new motor rotates in the correct direction before installing in the housing — apply 12V to the connector and observe rotation direction; a motor installed in the reverse orientation will draw air through the distribution ducts backward, producing dramatically reduced airflow and recirculating air from the cabin back through the filter housing; correct rotation direction is marked on the motor housing or specified in the vehicle service data.
  6. Install the new MOTOR SUB-ASSY (GREAT WALL 3747100K00), tighten the mounting screws evenly to avoid distorting the motor flange seal, reconnect the wiring connector, reconnect the battery, and test all blower speed settings from minimum to maximum before refitting the dashboard trim panel — confirm smooth, vibration-free operation at all speeds and correct airflow direction from all selected distribution outlets before completing the repair.
Tools: multimeter and 12V test leads for direct motor test, trim panel removal set, vacuum for housing cleaning, torch for debris inspection, screwdriver set for motor mounting screws.
Frequently Asked Questions
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How can a failed blower resistor pack be distinguished from a failed blower motor before disassembly?
The definitive test requires no disassembly: locate the blower motor connector and apply 12V directly to the motor terminals while the vehicle ignition is off. If the motor runs strongly on direct power, the motor is serviceable and the fault is in the speed control circuit — resistor pack, relay, or PWM module. If the motor does not run on direct power, or runs weakly and draws abnormally high current, the motor has failed internally. This single test eliminates the most common misdiagnosis of blower motor failure when the actual fault is a failed resistor pack — a component that costs a fraction of the motor and requires minimal labour to replace. ok.parts supplies blower motors at wholesale MOQ from 1.31 USD per unit.
Is recalibration or adaptation required after fitting a replacement blower motor on automatic climate control systems?
On most vehicles with automatic climate control the replacement motor is recognised immediately without adaptation — the climate control module drives the motor by PWM signal and monitors cabin temperature via the in-cabin sensor; it self-adjusts the duty cycle to maintain the temperature target regardless of minor variations in the replacement motor's speed-versus-voltage characteristics. On vehicles with fully digital HVAC systems that include blower motor current monitoring for fault detection — certain BMW, Mercedes-Benz, and Volvo platforms — a fault code reset via scan tool is required after replacement to clear the stored motor fault and allow the system to establish a new current baseline for the replacement motor's characteristics.
How does the OEM-equivalent aftermarket unit compare to the genuine OEM part?
OEM-equivalent units in this catalogue replicate the current OEM design geometry and material specification. Quality is verified against OEM cross-reference data. When ordering in bulk, confirm with our team that the specification matches the latest OEM revision for your application.
Is white-label or custom packaging available for wholesale orders?
Yes. ok.parts works directly with the manufacturing facility and can accommodate neutral white-label packaging or fully branded packaging with your company logo, part numbers, and barcode. Minimum order quantities and lead times for custom packaging may differ from standard stock. Contact the team via the inquiry form to discuss your specific requirements.
Frequently Replaced Together
PartReason for Combined Replacement
Blower Resistor Pack / Speed Control Module
OEM ref. varies by HVAC system type		The blower resistor pack or PWM control module is located in the blower airstream to dissipate the heat generated by speed reduction and is accessible during blower motor replacement on most vehicles. A resistor pack that has failed on lower speed stages is frequently the primary fault rather than the motor itself — always test the resistor before motor replacement. If the motor has failed due to overheating from a blower resistor that caused the motor to run at abnormally high current, replace both simultaneously.
Cabin Air Filter
OEM ref. varies by vehicle		A blocked cabin air filter is the most common cause of blower motor overheating and premature failure — the motor works against excessive backpressure, draws higher current, and runs hotter than its design rating. Fitting a new motor behind an old overloaded filter recreates the exact conditions that caused the original failure. Always replace the cabin filter simultaneously with the blower motor and inspect the filter housing for accumulated debris that contributed to the restriction.
HVAC Blend Door Actuator
Temperature or distribution actuator, OEM ref. varies		The blend door actuators controlling air temperature distribution and vent selection are located in the same HVAC housing as the blower motor and are often accessible during the same dashboard disassembly. On vehicles where a blend door actuator is producing noise or incorrect temperature distribution alongside the blower fault, replacing both during the same access operation eliminates a repeat dashboard removal within a short period and completes a full HVAC system service in one visit.