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Details
| Specification | Value |
|---|---|
| Brand | ASTEMO-HITACHI |
| Voltage [V] | 14.5 V |
| Manufacturer Restriction | OE VALEO |
OE numbers (9)
Search by this OE number to find compatible parts
- VW—028903029R
- SEAT / VW—038903803J
- AUDI / SEAT / SKODA / VW—038903803K
- AUDI / VW—06B903803
- AUDI / VW—06B903803A
- AUDI / VW—06B903803B
- AUDI—078903803C
- BMW—12427516175
- SEAT—77903803
Where this part fits
Original-fit position for OE 06B903803A. The red ring marks where this part installs on the vehicle.
About this product
Sourced from ASTEMO-HITACHI, this alternator regulator (2500731) combines precision engineering with durable materials to meet the demands of everyday driving and extended service intervals. Technical specifications — Voltage [V]: Nylon, Rubber V, Manufacturer Restriction: OE VALEO — are verified against the OEM data sheet to guarantee fitment accuracy and performance parity with the original equipment. Verified to fit ALFA ROMEO, AUDI, BMW, CITROËN and 15 other makes models. All compatibility data is cross-checked against the TecDoc database — select your vehicle to confirm the part matches your specific engine and year. This part supersedes original equipment references: 028903029R, 038903803J, 038903803K, 06B903803 and 231 more. Matching these numbers confirms a like-for-like replacement with no loss of function. ASTEMO-HITACHI is a recognised supplier of automotive replacement components to independent workshops and dealer networks across Europe. All parts are sourced from authorised distribution channels and carry full manufacturer traceability — you receive exactly the same component supplied to professional garages and dealer workshops. If fitment or specifications do not match your vehicle, our technical team can help identify the correct alternative — use the vehicle selector or contact us with your VIN for a guaranteed-fit recommendation. Replacing worn components on schedule preserves your vehicle's safety, reliability, and resale value — and aftermarket parts from established brands deliver OEM-equivalent performance at a fraction of the dealer price. Every part is dispatched with tracked delivery and a 14-day money-back guarantee with hassle-free returns.
Suitable cars
Equivalent products (200)
Show all 200 OE numbers
Alternator Regulator ASTEMO-HITACHI 2500731 — compatible car models
| Car models | ALFA ROMEO: 145 (930), 146 (930); AUDI: 100 C4 Avant (4A5), 100 C4 Saloon (4A2), 80 B4 Avant (8C5), 80 B4 Saloon (8C2), A2 (8Z0), A3 (8L1), A3 (8P1), A3 Sportback (8PA), A4 B5 (8D2), A4 B5 Avant (8D5) (+18 more) |
|---|---|
| Engines | 1.4 i.e. (930.A3); 1.4 i.e. (930.B3); 2.3 E; 1.9 TD; 1.4; 1.6; 1.8 T; 2.0 TDI; 1.9 TDI; 1.8; 3.0 quattro; 2.8; 3.0; 2.7 T quattro; 2.6 (+1 more) |
| Year of manufacture | 1988-2015 |
| Manufacturer article number (MPN) | 2500731 |
| OE part numbers | 028903029R, 038903803J, 038903803K, 06B903803, 06B903803A, 06B903803B, 078903803C, 12427516175, 77903803 |
Compatibility check
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Please wait while we load vehicle compatibility information.Description and what's included
ASTEMO-HITACHI 2500731 . Manufacturer Restriction: OE VALEO. Voltage [V]: 14,5 V
- 1x Alternator Regulator
Shipping, returns, warranty
Free UK delivery on orders over £99.00. Tracked standard shipping.
- Standard delivery: 5–9 business days
- Order before 5pm — ships the next working day
- Free returns within 14 days
- All parts backed by manufacturer warranty
Warranty: 12-month manufacturer warranty on all parts. 14-day money-back guarantee if the part doesn't fit your vehicle.
Frequently Asked Questions
Is this Alternator Regulator compatible with my car?
This Alternator Regulator fits ALFA ROMEO, AUDI, BMW, CITROËN, FIAT and 14 more vehicles. Use the vehicle selector at the top of the page to check exact compatibility — enter your car's make, model, and engine for a confirmed fitment match. All fitment data is verified through TecDoc.
What specifications does this ASTEMO-HITACHI Alternator Regulator have?
This ASTEMO-HITACHI Alternator Regulator has the following specifications: Voltage [V]: 14,5 V; Manufacturer Restriction: OE VALEO. Check the full specifications table above for complete details.
What OE part numbers does this Alternator Regulator replace?
This Alternator Regulator replaces OE part numbers: 028903029R, 038903803J, 038903803K, 06B903803, 06B903803A, 06B903803B, 078903803C, 12427516175 and 1 more. Cross-reference these numbers with your vehicle's original part number to confirm compatibility.
How much does a Alternator Regulator cost?
This ASTEMO-HITACHI Alternator Regulator is available for £54.99. Alternator Regulator prices vary depending on brand, specifications, and vehicle compatibility. ASTEMO-HITACHI parts offer a balance of quality and value, backed by our 14-day money-back guarantee.
How do I know when to replace my Alternator Regulator?
Regular inspection of your Alternator Regulator is recommended as part of routine vehicle maintenance. Watch for changes in performance, unusual noises, or visual signs of wear. Consult your vehicle's owner manual for manufacturer-recommended replacement intervals specific to your make and model.
What tools do I need to replace a Alternator Regulator?
Tools required vary by vehicle make and model. Generally, a basic socket set, screwdrivers, and vehicle-specific tools may be needed. We recommend consulting a workshop manual for your specific vehicle, or having the Alternator Regulator fitted by a professional mechanic.
Can I use this part as a replacement for OE 028903029R?
Yes, this ASTEMO-HITACHI Alternator Regulator is a direct replacement for OE part number 028903029R. It is manufactured to meet or exceed original equipment specifications, ensuring proper fitment and performance. All cross-reference data is verified through TecDoc.
Related categories
Common OE numbers for this part
Common original equipment numbers linked to stocked alternatives.
