12V Regulator Alternator 41-8851 Fit Thermo King NSD-II M3 Series, R6-M5 422395

12V Regulator Alternator for Thermo King NSD-II M3 Series

This 12V regulator alternator is a direct-fit charging solution for Thermo King NSD-II M3 Series engines, including the R6-M5 model, with the OEM reference 422395. It combines the alternator and regulator into one unit to simplify service and restore proper voltage output. This unit helps keep the reefer's electrical system stable during long hauls.

Overview

This 12V regulator alternator replaces the factory unit on Thermo King NSD-II M3 Series engines, providing regulated charging current for the battery and electrical components. It integrates the voltage regulator directly, matching the 422395 OEM design for a straightforward swap on the R6-M5 engine version. This 12V regulator alternator is intended for refrigeration units that need dependable power in cold-chain transport.

Built For Performance

• Integrated 12V regulator maintains output between 13.5 and 14.5 volts
• Direct fit for OEM part number 422395
• Targeted for NSD-II M3 Series engines, including the R6-M5
• Robust terminal connections withstand vibration from continuous running
• Low-draw standby mode reduces battery drain when the unit is off
• Compact mounting points replicate the original alternator footprint

Fits These Machines

• for Thermo King NSD-II M3 Series
• for Thermo King R6-M5

On-The-Job Use

• Charges the battery during long refrigerated routes
• Powers the control panel and sensors without voltage sag
• Rapidly recovers charge after starter motor cranks the engine
• Serves as a drop-in service replacement for the 422395 alternator

Specs At A Glance

Good To Know

Q: Is the regulator pre-installed inside the housing? A: Yes, the regulator is built into the alternator as a single sealed unit, so no external box is needed.

Q: Can this be used on a non-M3 Thermo King engine? A: It is specifically matched to the NSD-II M3 Series mounting and harness, so other models may require different bracket adapters or connectors.

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