12V Alternator LR170-407B LR170-408T LR170-408C 23100-02N15 23100-02N18

Product Overview

The LR170-407B alternator (OE LR170-407B, 23100-02N15, 23100-02N18) is a new, OE-spec replacement charging component built for the Nissan TD27 diesel engine family using Hitachi-type alternators. Rated at 12V 70A with a 2PK pulley, this alternator delivers stable charging output so your battery stays topped up and your electrical system runs dependably.

This aftermarket unit matches the original charging-system requirements of the Nissan TD27 engine family and the LR170-407B-series alternator cross-reference. It adopts a dependable regulator and rectifier assembly for stable voltage control and charging performance. The unit is stocked in-house, backed by a 1-year warranty with a 10-day dispatch lead time. Reliable charging-output design guarantees dependable battery charge and electrical-system performance for your 12V vehicle.

Key physical specs: net weight 6.0 kg (gross 6.15 kg), overall dimensions 28 x 18 x 16 cm, supplied in a neutral kraft inner carton.

Nissan TD27 Engine Charging System

The Nissan TD27 diesel engine relies on a correct 12V alternator match so the battery is recharged reliably and the electrical load is covered under normal driving. This alternator uses a 2PK pulley designed to align precisely with the engine drive belt system, delivering stable charging operation after installation.

Technical Specifications

Engine Compatibility and Cross Reference

This alternator fits Nissan vehicles with the TD27 diesel engine family. Do not rely solely on the vehicle model for fitment validation; always verify the engine model, old-alternator OE number, output rating, pulley profile and terminal layout stamped on your original alternator housing.

Multiple OE numbers exist across different production batches and market specifications for this same alternator family, covering both hyphenated and non-hyphenated OEM formats. If your original alternator housing carries any one of the listed part numbers, the LR170-407B-series unit is 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 nameplate data on your old alternator: confirm the output is 12V 70A. Different output ratings are not interchangeable.

• 2. Count the pulley ribs: this unit uses a 2PK (2-rib) pulley. An incorrect pulley profile will cause belt slippage and poor charging.

• 3. Confirm your vehicle is a Nissan TD27 diesel engine application. Other engines use different alternator assemblies.

• 4. Match the OE / reference part numbers stamped on your original alternator housing.

• 5. Weight cross-check: a genuine matching unit weighs about 6.0 kg net; a significant weight difference indicates the wrong assembly or low-grade build quality.

Application Scenarios

• Independent repair shops and auto-electric workshops servicing Nissan TD27 diesel engine vehicles across Asia, Africa, the Middle East, Europe, Latin America and North America.

• Parts counters and jobbers stocking Nissan charging electrical components and Hitachi-type alternators.

• Nissan fleet operators, dealerships, maintenance facilities and wholesale parts distributors.

• Diesel-vehicle and commercial-truck specialists servicing TD27 charging systems.

• Maintenance teams restoring vehicles to factory-standard condition.

Installation Steps and Precautions

Installation must comply with the assembly specifications for low-voltage electrical equipment and the general requirements for engine charging systems. The following are standardized installation steps, including compatibility inspection and practical operation precautions, to ensure stable operation after installation.

Pre-Installation Preparation

• Power cut protection: Turn off the engine ignition switch and disconnect the negative battery cable to avoid short circuits caused by accidental circuit contact during installation.

• Tool preparation: Prepare a torque wrench, socket set, screwdriver, belt-tension gauge, wire harness clips, conductive paste, metal cleaner and rags. Have small accessories such as gaskets and spacers of the same specification ready.

Component and Compatibility Inspection

• Confirm the new alternator is the 12V 70A model and compatible with the engine of the target vehicle.

• Check that the alternator housing has no cracks, the pulley rotates freely without wobble or jamming, the cooling fan blades are intact, and the threaded terminals are not damaged.

• When replacing an old alternator, clean the oil stains and rust at the old installation position. Check the drive belt for cracks, glazing or wear; replace it if the belt is worn or its length is not suitable.

Cleaning the Installation Workstation

• The alternator is usually mounted at the front side of the engine. For some vehicles, first remove the surrounding air filter box, fan shroud or bracket components, and reserve sufficient operating space to prevent component interference during installation.

Securing the Main Body of the Alternator

• Firmly fit the alternator onto the mounting bracket. Align the pulley with the drive-belt groove and confirm the belt sits correctly in the 2PK pulley grooves without misalignment or twist.

• Pre-tighten 2-3 matching fixing bolts diagonally, then tighten them to the standard torque of 35+/-5 Nm with a torque wrench (fine-tune with reference to the corresponding Nissan maintenance manual). Insufficient torque leads to violent vibration during operation, while excessive torque may damage the housing or the bracket threads.

• Adjust the drive-belt tension with the tensioner to the Nissan workshop-manual specification. A belt that is too loose slips and causes low charging output; a belt that is too tight overloads the alternator bearing.

Connecting the Electrical Circuits

• Main output terminal (B+): Connect the thick output wire from the battery. Before connection, wipe the terminal with a cleaner to remove the oxide layer; if necessary, apply a small amount of conductive paste to reduce contact resistance. Tighten the terminal nut to 8+/-2 Nm to prevent the terminal from overheating and ablation when a large current passes through the charging circuit.

• Signal and sense terminals (L / S / IG): Connect the wiring harness plugs to the alternator signal, sense and ignition terminals according to the vehicle wiring diagram. Do not force-fit or reverse the plugs, and fix the harness with clips, keeping it away from rotating components and hot exhaust parts.

Finalization and Functional Testing

• Reinstall the previously removed components in sequence and confirm all shields and clips are properly installed. Reconnect the negative battery cable, tighten the terminal nut, and check for no looseness.

• Conduct a charging test: start the engine and measure the battery terminal voltage with a multimeter. At idle and at speed, charging voltage should read in the normal 13.5-14.5V range for a 12V system. Confirm the charging warning lamp on the dashboard goes out.

• If the battery is not charging, check the alternator output terminal connection and the drive-belt tension. If there is abnormal noise, check the pulley alignment, belt condition and alternator bearing.

FAQ

In Practice

For technicians working on Nissan TD27 platforms: before removing the existing alternator, perform charging-system diagnostics. Measure battery voltage with the engine off and running. Defective batteries, worn drive belts, loose output terminals, corroded cables or bad ground points can mimic alternator-failure symptoms, so do not replace the alternator blindly. Always disconnect the battery negative terminal before commencing removal work.

Take photos of wiring terminals and bolt positions during disassembly to avoid mis-wiring during reassembly. Inspect the drive belt for cracks and wear, and confirm the 2PK pulley alignment before fitting the new alternator, because a mismatched pulley will quickly damage the new belt and reduce charging output. Tighten mounting bolts to the Nissan official workshop-manual torque specifications.

References

The installation method and related precautions are standardized content summarized and integrated based on the universal assembly specifications of Nissan engine charging systems, industry installation standards for low-voltage alternators of the same specification, and practical experience in the automotive repair field. Equipment applications are compiled from original-equipment fitment data for the LR170-407B-series alternator family covering Nissan TD27 diesel engine applications.

About the Author

This article was written by the senior auto-electric technician team at Nuojin Auto Parts, with over 15 years of hands-on experience in automotive charging and starting systems.

Our engineers specialise in Japanese, European, Korean, American and Chinese vehicle charging-system diagnostics, aftermarket alternator and starter-motor cross-referencing, and factory-spec electrical-system restoration for global markets. Every product listing on this site is backed by real bench-tested fitment data and first-hand repair experience, not just copied from manufacturer manuals.

If you have any question about this alternator or your engine charging system, contact our technical team and we will help you confirm the correct part for your application.

Nuojin Auto Parts is a professional starter and alternator supplier based in Hejian, Hebei, China, running factory-grade bench testing on every production batch. We support distributors, wholesalers and repair shops worldwide with correct-fit sourcing, a 1-year warranty and responsive after-sales technical assistance.