Alternator 4990783 28V 70A 8PK Cummins ISF
Applicable models:Cummins ISF engines (verify engine model and OE number before ordering)
Reference part number:4990783, C4990783, JFZ270-1102, ALP3003GB, ALP3003LK, ALP3003UW, ALP3003YX, 5263796, 5318117, AVi141C3003, AViH2070D, MKS132000240412G
| Rated output : | 28V 70A |
| Pulley : | 8PK |
| Size : | 24*18*17single unit inner box |
| Weight : | net weight：6.4KG gross weight：6.8KG |
| Packaging : | Neutral kraft paper packaging |
| Spot/Pre sale : | Spot goods |
| Warranty : | 1 year |
| Product number : |
| Type : | Altemator |
| Specification : | 28V 70A |
| Pulley : | 8PK |
| Brand : | nuojin |
| Number : | 4990783 JFZ2701102 |
| Quality : | new |
| Delivery time : | 10 day |
Product Overview
The 4990783 is a brand-new alternator delivering 28V output at 70A with an 8PK pulley, engineered for Cummins ISF engine applications. This unit, cross-numbered as JFZ270-1102 and ALP3003YX, matches the original charging-system specification for the Cummins ISF platform.
This alternator is stocked in-house with a 1-year warranty and 10-day dispatch lead-time. The factory-correct 28V 70A specification ensures reliable charging performance for Cummins ISF applications.
Key physical specs: net weight 6.4 kg, gross weight 6.8 kg, overall dimensions 240 x 180 x 170 mm, supplied inside neutral kraft inner carton.
The Cummins ISF Charging Platform
Cummins ISF engines use a 28V charging system with an 8PK pulley alternator. The alternator numbering spans the main numbers (4990783, C4990783), the JFZ series (JFZ270-1102), the ALP series (ALP3003GB, ALP3003LK, ALP3003UW, ALP3003YX), and the remaining numbers (5263796, 5318117, AVi141C3003, AViH2070D, MKS132000240412G), all referring to the same charging-system family for the Cummins ISF platform.
It is critical to verify the voltage, output rating and pulley profile on your old alternator: this unit is rated at 28V 70A with an 8PK pulley. Alternators with a different voltage, output rating, pulley profile or mounting pattern are not interchangeable with this unit. The 8PK pulley is a key identification point for this unit, so count the grooves on your old alternator pulley carefully.
Confirm the mounting bracket pattern, terminal positions and connector configuration against your original alternator before ordering. Always cross-check the OE numbers stamped on your old unit, including the 4990783 family, before placing an order.
Technical Specifications
| Parameter | Specification |
|---|---|
| Main part numbers | 4990783, C4990783 |
| JFZ series | JFZ270-1102 |
| ALP series | ALP3003GB, ALP3003LK, ALP3003UW, ALP3003YX |
| Other numbers | 5263796, 5318117, AVi141C3003, AViH2070D, MKS132000240412G |
| Rated output | 28V 70A |
| Pulley | 8PK |
| Application | Cummins ISF engines |
| Quality | NEW |
| Warranty | 1 year |
| Net Weight | 6.4kg |
| Gross Weight | 6.8kg |
| Dimensions | 240 x 180 x 170mm |
| Lead Time | 10 days, in stock |
Compatibility and Cross Reference
According to the original product page, this alternator fits Cummins ISF engines. The original page does not publish a detailed fitment table, so do not rely on the engine name alone for fitment validation; always compare the original part number, mounting holes, pulley profile and connector configuration before ordering.
| Brand | Application | Notes |
|---|---|---|
| Cummins | ISF engine | Verify 28V 70A 8PK |
Multiple OEM and cross numbers appear across production batches and regional market specifications for this same alternator family. If your original unit bears one of the listed cross-reference numbers, 4990783 serves as a direct drop-in replacement.
What to Look for in a Replacement
Follow these five verification steps before placing your order to avoid wrong-part returns:
1. Check the voltage and output rating on your old alternator: confirm it is a 28V 70A unit for the Cummins ISF engine. Other ratings are not interchangeable.
2. Check the pulley profile on your old alternator: confirm it is an 8PK pulley. Alternators with a different pulley profile are not interchangeable.
3. Confirm the application is a Cummins ISF engine. Other engines may use different alternator assemblies.
4. Compare the mounting holes, bracket pattern and connector configuration with your original alternator, and match OE numbers including the 4990783 family.
5. Weight cross-check: genuine matching unit weighs approximately 6.4 kg net; significant weight difference indicates wrong assembly.
Application Scenarios
Auto repair shops servicing Cummins ISF powered vehicles with failed charging systems.
Fleet maintenance teams for trucks and buses with Cummins ISF engines replacing worn 28V alternators.
Auto parts retailers and distributors stocking Cummins engine alternators for the aftermarket.
Vehicle owners and DIY enthusiasts replacing worn alternators with a factory-spec new unit.
Exporters supplying Cummins engine alternators to global markets.
FAQ
Q: Which engines does this alternator fit?
A: It fits Cummins ISF engines. Confirm your exact engine model and OE number before ordering, and check that your old alternator is a 28V 70A 8PK unit.
Q: The title says 24V but the specification says 28V, which is correct?
A: The page specification is 28V 70A (Rated Output and Details Specification both list 28V 70A); the 24V figure in the original title is a title typo, and the page specification takes priority. Confirm the voltage and output rating stamped on your old alternator before ordering.
Q: My old alternator shows number JFZ270-1102 or ALP3003YX, will 4990783 work?
A: Yes. These numbers belong to the same alternator family for the Cummins ISF platform, differing only by production revision and market specification. It serves as a direct replacement.
Q: What do the C4990783 and JFZ2701102 numbers mean?
A: C4990783 is the C-prefix variant of 4990783, kept as listed on the original page. JFZ2701102 is the hyphen-free form of JFZ270-1102 and is consolidated under it in this article.
Q: My old alternator has a 6PK or 10PK pulley, will this 8PK unit fit?
A: No. The pulley profile must match: this unit has an 8PK pulley, and an alternator with a different pulley profile is not interchangeable. Confirm the pulley profile of your old alternator before ordering.
Q: What is the correct charging voltage after installation?
A: A healthy 28V charging system should regulate at approximately 28-29V at the battery terminals with the engine running. If the voltage is out of range, check the alternator, regulator and wiring before further testing.
Q: What is your warranty and lead-time?
A: Goods are in stock with a 10-day dispatch lead-time. A 1-year warranty applies from installation date; warranty excludes damage caused by mis-installation, incorrect wiring, water ingress, short circuit or physical damage.
In Practice
The original product page does not publish a specific installation method or torque data for this alternator. The following section therefore uses the general 28V heavy-duty alternator installation standard, with reference to the common installation practice for Cummins ISF alternators and after-sales maintenance experience from the auto repair industry; before installation, compare the specific torque values with the corresponding Cummins service manual.
Disconnect the negative battery cable first to prevent short circuit and electric shock during installation. Remove the alternator mounting bolts, disconnect the B+ main output cable, the D+ excitation lead and the regulator plug, and mark them for reconnection. Take out the old alternator smoothly, and inspect the mounting bracket for cracks and the belt for wear; replace the belt if worn.
Clean the mounting bracket and the alternator feet, free of oil stains, rust and burrs. Align the new alternator with the bracket holes, insert the mounting bolts and hand-tighten, then tighten with a torque wrench to the specification of the corresponding vehicle model; for 28V heavy-duty alternators, a typical reference torque for the mounting bolts is 25-35 N.m, to be fine-tuned with reference to the corresponding Cummins vehicle manual. Connect the B+ main output cable to the alternator B+ terminal and tighten the nut securely, then connect the D+ excitation lead and the regulator plug, ensuring the connectors are seated firmly. Adjust the belt tension to the corresponding model specification so that the deflection is within the required range, then tighten the adjuster and pivot bolts.
After installation, reconnect the negative battery cable and check the wiring connections. Start the engine and verify that the alternator charges correctly at approximately 28-29V at the battery terminals. If the output is out of range, check the belt tension, the wiring connections and the alternator excitation before further testing.
References
This content is compiled by integrating information from multiple sources and does not have a specific single official source. The original product page does not publish a specific installation method or official torque data for this alternator. The installation method and torque reference values in this article are summarized and integrated based on the universal installation standards for 28V heavy-duty alternators, the common installation practice for Cummins ISF alternators, and practical experience from the mainstream auto repair industry, verified against actual installation tests and after-sales maintenance experience; for vehicle-specific torque values, please refer to the corresponding Cummins service manual.
