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| SERVICE | DELIVERY PRICE | DELIVERY TIME |
|---|---|---|
| Standard Delivery | £9.95 | 7 to 10 working days |
| SERVICE | DELIVERY PRICE | DELIVERY TIME |
|---|---|---|
| Standard Delivery | £9.95 | 7 to 10 working days |
| SERVICE | DELIVERY PRICE | DELIVERY TIME |
|---|---|---|
| Standard Delivery | £4.99 | 1 to 2 working days |
| SERVICE | DELIVERY PRICE | DELIVERY TIME |
|---|---|---|
| Standard Delivery | £9.95 | 5 to 7 working days |
| SERVICE | DELIVERY PRICE | DELIVERY TIME |
|---|---|---|
| Standard Delivery | £9.95 | 7 to 10 working days |
Product Number: 12739N
The WAI 12739N is a brand-new 12V 120A alternator. It is built to the Marelli IR/IF design, cross-referenced against 62 OE and aftermarket references including Denso 102211-8120, Denso 102211-8130, Delco Remy DRA0028, DRA0029, PERKINS 2871A309, and Magneti Marelli 063377463010. It is a direct-fit replacement for Caterpillar agricultural and industrial machines and JCB equipment — 16 verified applications in total.
The IR/IF (internally regulated, internally fused) architecture keeps voltage regulation electronics inside the unit, reducing external wiring complexity and making like-for-like fitment straightforward on machines where the original was a Marelli-design unit. Clockwise rotation matches the drive direction of the supported Caterpillar and JCB engines. The alternator is supplied without a pulley, so the existing pulley from the unit being replaced is carried over — confirm your pulley bore and belt profile before ordering.
Verified Caterpillar applications include the 420D, 432D, 432E, 432F, D3K, D3K LGP, D3K XL, and D4H LGP; JCB applications bring the total fitment count to 16. With 62 cross-references spanning Denso, Delco Remy, Perkins, Iskra / Letrika, Magneti Marelli, and Letrika, the 12739N covers a wide spread of OE sourcing histories across those platforms.
About PartsForMachines:
PartsForMachines is a premier e-commerce platform, founded in 2019 in Warwickshire, UK, specializing in aftermarket parts and services for construction, agriculture, and industrial machinery. We offer an extensive catalog of over 500,000 products. Standard delivery: 1–3 working days within UK mainland. We are proud to be an authorised distributor, giving customers extra confidence when purchasing genuine products from us. In addition, we provide a 30-day return policy for eligible items.
| Type | Alternator |
|---|---|
| Manufacturer | Marelli |
| Design | IR/IF |
| Voltage | 12V |
| Output | 120A |
| Rotation | CW |
| Pulley | w/o Pulley |
| Condition | Brand New |
| Engine Parts | Product Number | Product Name | Recommended Units | Product Price |
|---|
Exploring the WAI Starter Motor and Alternator at Partsformachines.com Introduction: In the Plant and Agriculture sector, a starter motor and alternator are parts that ensure a machine runs smoothly. At Partsformachines.com we have partnered with WAI, a global manufacturer of auto and plant machinery parts to off...
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| Technical Specification | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PRODUCT NUMBER | 14482N | 20539N | 21610N | 23853N | 21173N | 22155N | 23791N | 8440N | A4033 | A4058 | A4072 | A4084 | A4085 | A4103 | A9012 |
| Voltage | 12 | 12 | 12 | 12 | 12 | 12 | 12 | 12 | 12 | 12 | 12 | 12 | 12 | 12 | 12 |
| Output Current | 120 | 124 | 90 | 90 | 110 | 90 | 100 | 105 | 70 | 80 | 70 | 85 | 110 | ||
| Design | IR/IF | IR/IF | IR/IF | IR/IF | IR/IF | IR/IF | |||||||||
| Manufacturer | Marelli | Marelli | Electroprecizia | VISTEON | Marelli | Ford | Mando | Ford | |||||||
| Pulley | COUPLER | S6 | S6 | SC7 | S6 | AP | AP | AP | AP | AP | AP | ||||
| Rotation | CW | CW | CW | CW | |||||||||||
A. This alternator fits Caterpillar agricultural and industrial machines — including the 420D, 432D, 432E, 432F, D3K, D3K LGP, D3K XL, and D4H LGP — as well as JCB equipment, covering 16 verified applications in total. Use the selection widget to match your exact make, model, and engine variant, or search our cross-referenced catalogue by OEM number or machine model. Every fitment shown is backed by our Fit Guarantee.
A. Yes. The WAI 12739N carries 8 Denso references in its 62-reference cross-reference list, including Denso 102211-8120, Denso 102211-8130, Denso Aftermarket DAN1091, DAN1092, and DAN650, Denso DAN649, and Denso OEM 1022118120 and 1022118130. If you are sourcing by Denso number, any of those references confirmed in our catalogue will route you to this part.
A. Yes — both PERKINS 2871A309 and Perkins 3832557 are listed cross-references for the WAI 12739N. Search our catalogue by either number to confirm fitment against your specific engine application.
A. Yes. The WAI 12739N cross-references Delco Remy DRA0028, DRA0029, and DRA0029N. If your machine was originally fitted with a Delco Remy unit bearing any of those numbers, this alternator is the catalogued replacement.
A. The 12739N is supplied without a pulley — you will need to transfer the existing pulley from the unit being replaced. Confirm your pulley bore and belt profile before installation. The rotation direction is clockwise (CW), matching the original Marelli IR/IF specification for the supported Caterpillar and JCB applications.
A. The WAI 12739N cross-references six Iskra / Letrika numbers, including Iskra / Letricka tech 11203175, Iskra / Letricka tech 11203433, Iskra / Letrika commercial IA1203 and IA1204, and Iskra / Letrika family AAK5384 and AAK5580. It also carries four Magneti Marelli references: 063377463010, 063377464010, 63377463, and 63377464, plus Letrika references 11.203.175 and 11.203.433. The full list of 62 cross-references is searchable in our catalogue.
A. IR/IF stands for internally regulated and internally fused. The voltage regulator is housed inside the alternator body rather than mounted externally on the machine, and the internal fusing is self-contained. This matches the original design specification of the Marelli units fitted to the supported Caterpillar and JCB machines, making it a like-for-like replacement without requiring changes to external wiring.
A. Use the selection widget on this page to match by make, model, and engine variant, or search our cross-referenced catalogue by your existing OEM part number. If your machine is not listed, ask Simon. Every fitment shown is backed by our Fit Guarantee — if it is not right, our Fit Guarantee or hassle-free returns have you covered.
A. Compatible spares and accessories are shown on the Related Accessories tab of this product page, and common parts across the brands we stock are in our Parts & Spares section.
A. Yes — ask Simon, or WhatsApp our team on 07754 288583 with any questions about specifications, suitability, or compatibility.
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