4B0820521 Blower Motor Regulator for Audi A6 (C5) and Allroad Quattro Series

Cross Reference Numbers for Blower Motor Regulator 4B0820521

Category	Brand / Manufacturer	Reference Number
OE Number	VAG Group (Audi)	4B0820521 (4B0 820 521)
Major Aftermarket Brands	VEMO (Germany)	V10-79-0004
	NRF	342045
	METZGER	0917056
	Meyle	100 800 0036
Interchange Part Nos.	Topran / Hans Pries	109 313
	Febi Bilstein	23147
	Automega	150035510

Specification for Blower Motor Regulator 4B0820521

Technical Parameter	Professional Specification
Control Logic	Advanced PWM
Heatsink Material	High-Thermal Flux Aluminum Alloy
Operating Voltage	12V DC
Terminal Configuration	5-Pin Heavy-Duty Connector
Housing Material	PA66 + 30% GF
Protection Grade	IP54 Dust & Moisture Resistant
Signal Response	Linear Voltage Output for Stepless Speed Change
Standard	IATF 16949 / ISO 9001

Vehicle Application for Blower Motor Regulator 4B0820521

Brand	Model	Year Range	Engine & Fitment Notes
Audi	A6 / S6 Saloon (4B2, C5)	1997 – 2005	1.8T, 2.4, 2.7T, 2.8, 3.0, 4.2
Audi	A6 Avant (4B5, C5)	1997 – 2005	All Wagon / Estate Variants
Audi	Allroad Quattro (4BH, C5)	2000 – 2005	2.5 TDI, 2.7 Turbo, 4.2 V8
Audi	A6 Quattro	1998 – 2004	Heavy-Duty AWD HVAC Loads

Why Choose Elecdura as Your Blower Motor Resistor Supplier

Elecdura Blower Motor Resistor Wholesale & Logistics Services

• Custom Branding Solutions: All units are supplied in neutral packaging by default, with full support for customized labels, private-label packaging, and logo printing to enhance your brand presence.

• Flexible Bulk Ordering: Our standard Wholesale MOQ starts at 100 units per item, and we encourage you to discuss any specific volume requirements or custom terms with our dedicated sales team.

• Ready-to-Distribute Supply: We provide high-quality finished products ideal for rapid distribution, with a reliable 60-day production lead time for all wholesale orders to ensure your inventory stays consistent.

Elecdura Blower Motor Resistor Partner Factory Tour

Why Choose Elecdura for Blower Motor Resistor?

1. Backed by Tier-1 Manufacturing Excellence

Our resistors are manufactured in China’s top-tier automotive facilities, which serve as trusted OEM suppliers for global automotive giants such as BYD, Geely, and Chery, as well as renowned international aftermarket brands like Valeo, NRF, and Dorman. By choosing Elecdura, you gain access to the same rigorous production standards and technical expertise required by the world's leading car manufacturers.

2. Optimized Price-Performance through Strategic Sourcing

As a specialized automotive aggregator, Elecdura does more than just sell parts—we manage a premium factory network. We conduct deep comparisons across multiple top-scale manufacturers to select the optimal balance of quality and cost. This allows us to provide you with a product that matches OE reliability while maintaining a competitive price edge that factory-direct models often cannot offer due to their rigid pricing structures.

3. Proven Market Success and Supply Stability

The Blower Motor Resistor is a cornerstone of our thermal management line with a proven track record. We currently supply high-volume orders to major international wholesalers, meaning our products are already "battle-tested" in the global aftermarket. This ongoing, stable production ensures that we have both the refined quality control and the massive capacity to fulfill your bulk requirements without lead-time fluctuations.

4. Professional Quality Assurance & Testing

Leveraging our partners' advanced laboratory capabilities, every batch of our resistors undergoes 100% End-of-Line testing. From salt spray resistance to thermal cycling, we ensure that the components you receive are built to survive extreme conditions, significantly reducing your RMA (Return Merchandise Authorization) rates and protecting your brand reputation.

Blower Motor Resistor Successful Aftermarket Case

4B0820521 Blower Motor Resistor Wholesaler Frequently Asked Questions

1. How does the 4B0820521 handle the dual-zone temperature logic of the A6 C5?

Our regulator is fully synchronized with the C5's Climatronic control head. It accurately translates digital requests into voltage adjustments, ensuring that the blower motor delivers the exact CFM (Cubic Feet per Minute) required for both driver and passenger zones.

2. Why is the heatsink geometry important for Allroad models?

The Allroad Quattro often operates under higher engine bay temperatures. We use an optimized vertical fin design for the aluminum heatsink, which maximizes natural convection and airflow cooling, preventing thermal shutdown during long trips.

3. Does this regulator solve the "Intermittent Fan Speed" issue common in C5 Audis?

Yes. "Intermittent pulsing" or "stuck speeds" are usually caused by failing internal transistors in the regulator. We use high-specification automotive MOSFETs to ensure a clean, stable output, eliminating the fluctuating fan speeds common in aging vehicles.

4. Is this 5-pin unit compatible with early 1997 models?

While 4B0820521 covers the vast majority of the C5 production run, we recommend checking the original unit's pin pattern. For vehicles produced before 05/1997, some regional variants may have used a different electrical relay setup.

5. What is the standard wholesale MOQ for Elecdura’s VAG regulators?

Our MOQ for the 4B0820521 is 100 units. We offer competitive tiered pricing for container-load orders to Europe and North America to minimize landed costs for our partners.

6. Do you offer private labeling for major European auto parts brands?

Yes. For wholesale orders (MOQ 100+), we can laser-etch your custom part numbers and logos onto the PA66 housing and provide customized retail packaging to support your local brand strategy.