Core Product Function
81.25902.0410 Auxiliary Relay 20A is a dedicated electrical control component for heavy-duty trucks (SINOTRUK HOWO, SHACMAN, FOTON AUMAN series). It serves as a signal conversion and power amplification hub in the vehicle electrical system, controlling the on-off of high-current electrical circuits (such as lights, wipers, air compressors, and auxiliary electrical appliances) through small-current signals. It protects the vehicle's original control switches from burnout due to overcurrent, stabilizes the operation of electrical components, improves the reliability of the entire vehicle electrical system, and adapts to harsh working conditions such as low temperature, high humidity, and strong vibration during heavy-duty truck operation.
Adaptability and Compatibility
Applicable Vehicles: MAN series heavy‑duty trucks, SHACMAN X3000 / F3000 / M3000, Sinotruk Howo T5G / T7H / C7H
Adaptable Systems: Whole vehicle electrical system, lighting system, auxiliary motor control circuit
OE Reference Number: 81.25902.0410Interchangeable Number: 2991711
Interchangeability: Direct plug‑and‑play replacement for original parts, no wiring modification
Value‑added Service: Support VIN configuration verification
Key Technical Parameters
Main Dimensions: 28±1mm × 25±1mm × 35±1mm
Contact Configuration: 5‑pin dual 20A
Rated Voltage: 24V DCRated Current: 2×20A
Contact Material: Silver alloyOperating Temperature: ‑40℃ ~ 125℃
Waterproof Grade: IP54
Electrical Life: ≥ 100,000 operations
Mechanical Life: ≥ 10 million operations
Coil Resistance: Standard matching vehicle circuit
Materials and Processes
Core Materials: Silver‑tin alloy contacts, high‑temperature resistant copper coil, flame‑retardant PA66 housing
Surface Treatment: Insulation coating on coil, anti‑vibration and anti‑corrosion housing
Production Process: Automatic winding, precision stamping, sealed injection molding, 100% energized test before delivery
Production Line Capacity: Self‑owned molds, monthly output ≥ 50,000 units
Quality Grade and Inspection
Quality Grade: High‑quality aftermarket parts, fully compliant with OE technical standards
Inspection Items: Contact resistance test, voltage withstand test, temperature rise test, vibration test, waterproof test
Quality System: IATF16949, ISO9001 certified
Batch Tracking: Full traceability with batch number and production date
Service Life and Performance
Average Service Life: ≥ 3 years or 300,000 kilometers
Performance Advantages: Low contact resistance, low heat generation, high temperature resistance, anti‑vibration, anti‑interference
Harsh Environment Adaptation: Stable starting at ‑40℃, no contact ablation or burnout at high temperature; suitable for cold, humid, dusty, and high‑vibration working conditions
Fault Improvement and Replacement Value
Common Fault Improvement: Solves issues such as poor contact, frequent burnout, weak load capacity, and malfunction of original relays
Maintenance Value: Direct plug‑in replacement, reduces repair time by 50%; high reliability lowers failure frequency and vehicle downtime
Packaging and Marking
Packaging Configuration: Anti‑static bag + shock‑proof foam + carton + moisture‑proof agent
Carton Marking: OE number, product name, quantity, batch number, gross/net weight
Product Marking: Laser marking of OE number, voltage, current, batch
Customization: Support neutral packaging and customer‑branded packaging
Supply Capacity
Inventory Status: In stock
MOQ: 10 pieces
Delivery Time: 3 days for stock orders; 7–15 days for bulk orders
Supply Stability: Monthly output ≥ 50,000 units, stable year‑round
Certification and After‑sales Guarantee
Certification: IATF16949, ISO9001; third‑party test reports available
Warranty: 18‑month warranty
After‑sales: 7‑day free replacement for non‑human damage; 24‑hour online technical support
Return Policy: Accept returns for non‑human damage, supplier covers freight
Scenario Cases
Northern China: Stable operation for 3 years in ‑35℃ low temperature, no relay failure
Northwest Desert: Dust‑proof and vibration‑proof, service life exceeds 350,000 km
Southeast Asia: Adapted to high temperature and humidity, lighting and control circuits work normally
Maintenance and Precautions
Installation: Plug directly into original socket, ensure firm contact; do not reverse polarity.
Inspection: Check for looseness, overheating, or abnormal function every 30,000 km.
Storage: Keep dry and ventilated; avoid moisture, oil, and extrusion.
Replacement: Replace immediately if there is poor contact, frequent tripping, or failure to actuate.
Frequently Asked Questions (FAQ)
Q1: Does it support VIN compatibility check?
A1: Yes, we can verify fitment by VIN code.
Q2: Does it meet original factory standards?
A2: Yes, fully meets OE specs and passes IATF16949 certification.
Q3: Can you provide samples?
A3: Yes, sample fee deductible from formal orders.
Q4: What payment methods are supported?
A4: T/T, L/C, Western Union, PayPal, Alipay, WeChat Pay.
Hot Tags: 81.25902.0410 auxiliary relay 20a, China 81.25902.0410 auxiliary relay 20a manufacturers, suppliers, factory, SHACMAN Relay Truck, Relay Truck Spare Parts, Rear Fog Lamp Relay, 81 25902 0460 5 pin Window Regulator Relay, 81 25902 0469, 81 25902 0469 Rear Fog Lamp Relay
