12V Alternator 41-8851 Fit Thermo King SB-400 Tier 2 Engine SB-II with D'201

12V Alternator for Thermo King SB-400 Tier 2 Engine

This 12V alternator is a reliable direct replacement for Thermo King SB-400 Tier 2 engines, delivering consistent charging output for your refrigeration unit. It fits the SB-II system and works seamlessly with the listed OEM cross-reference D'201. This alternator keeps the battery charged and the reefer running smoothly under continuous load.

Overview

This 12V alternator is built to power the electrical system of a Thermo King SB-400 Tier 2 engine, supplying steady current for ignition, controls, and battery charging. It is designed for the specific mounting and pulley configuration of SB-II models, using the D'201 reference for compatibility. This 12V alternator provides the amperage needed for reliable cold-chain performance in over-the-road and stationary refrigeration applications.

Built For Performance

• Rated at 12V for consistent charging output
• Direct replacement for 41-8851 and D'201 OEM references
• Precision-wound stator and rotor for stable voltage under variable RPM
• Sealed bearings to resist moisture and road grime
• Heavy-duty diode pack handles repeated electrical load spikes
• Compact housing engineered to fit the SB-400 Tier 2 engine bay

Fits These Machines

• for Thermo King SB-400 Tier 2
• for Thermo King SB-II

On-The-Job Use

• Maintains battery charge during multi-stop delivery routes
• Supports continuous operation of refrigerator control modules
• Handles high electrical demand in hot ambient conditions
• Replacement for worn-out charging systems in aging reefer fleets

Specs At A Glance

Good To Know

Q: Will this alternator work if my unit has a different pulley? A: The alternator is built to the factory 41-8851 specifications, but if a pulley or mount has been modified, verify the shaft diameter and mounting ears before installation.

Q: Does this include the voltage regulator? A: No, this is the bare alternator unit; the regulator is separate and must be ordered if needed.

Slight variation in finish or dimensions may occur between production runs, and fit can depend on serial number, so confirm compatibility before ordering.