12V Regulator Alternator 41-8851 MP300 Fit Thermo King AT11 AT12 Coach RT 1012

Regulator Alternator for Thermo King

This 12V Regulator Alternator, cross-referenced as 41-8851 and MP300, is designed for Thermo King coach and bus units, including AT11, AT12, and RT 1012 models.

Overview

This 12V Regulator Alternator 41-8851 MP300 is a replacement charging unit for Thermo King transport refrigeration systems in coaches and buses. It provides regulated output to keep batteries charged and systems running reliably. This regulator alternator is built to meet the electrical demands of Thermo King AT11, AT12, and RT 1012 units.

Built For Performance

• 12-volt regulation protects downstream electrical components
• Direct cross-reference to OEM numbers 41-8851 and MP300
• Designed for the vibration and duty cycle of coach applications
• High-output design supports auxiliary loads in transit
• Sealed internals help resist moisture and debris ingress

Fits These Machines

• for Thermo King AT11
• for Thermo King AT12
• for Thermo King RT 1012

On-The-Job Use

• Charges batteries in coach HVAC systems during long haul operations
• Supplies steady power for Thermo King control modules and fans
• Ensures starting capability after extended idle periods

Specs At A Glance

Good To Know

Q: Which Thermo King units does this alternator serve? A: This regulator alternator is compatible with Thermo King AT11, AT12, and RT 1012 coach units, as well as other applications using the 41-8851 or MP300 part number.

Q: How does this part help maintain system performance? A: It maintains proper voltage so the refrigeration unit’s controls and electric motors operate within designed parameters. This prevents under-charging and electrical system strain in daily coach service.

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