Thermo King Weatherproof Magnetic Door Switch 400477
Official OEM Thermo King parts catalog entry for the Kit Door Switch 400477, verified by PEAK Thermo King and West Texas Thermo King Texas, Utah, Wyoming, Washington, Oregon, serving all of the USA.
Built for Performance: The Thermo King Kit Door Switch 400477 supports Thermo King refrigeration system integration and delivers reliable door-status control for reefer trailers and transport refrigeration applications. Engineered for fleets that demand uptime and precise temperature control, this door switch assembly helps protect loads and improve fuel-efficient cooling across regional and long-haul operations.
Key Features & Customer Benefits
- Automatic Unit Control – Stops refrigeration unit runtime when doors open to reduce fuel consumption and maintenance hours.
- Weatherproof Construction – Sealed switch and magnet assembly withstands trailer environments for consistent reliability.
- 3‑Wire Compatibility – Integrates with Thermo King control inputs (use 18 AWG or better harness) to support accurate door-status reporting.
- Low‑Profile Magnetic Mount – Minimizes snag risk and fits swing-out or roll-up doors for seamless retrofit and OEM installs.
- Improved Temperature Protection – Limits heat ingress during loading to preserve cold chains for temperature-sensitive cargo.
- Fleet ROI – Reduces unnecessary run time on Smart Reefer and Diesel Direct Electric units, supporting lower operational costs and extended service intervals.
Product Details
| Part Number | 400477 |
| Function | Magnetic door switch assembly for automatic refrigeration unit control and door-status sensing |
| Construction | Weatherproof, low-profile switch and magnet; solid-state sensing electronics |
| Harness | 3-wire recommended (RED = power, BLACK = ground, WHITE = output); 18 AWG minimum |
| Mounting | Non-magnetic mounting hardware; maximum gap 19 mm (0.75 in.) between switch and magnet |
| Compatibility | Thermo King refrigeration units and reefer trailers that accept door-switch inputs; consult service manual for exact fitment |
Efficiency & Sustainability
This door switch supports fuel-efficient cooling by reducing unnecessary run time on Thermo King units, contributing to lower emissions and operating costs. It integrates with advanced controls such as Smart Reefer SR-4 and complements CARB Evergreen compliance strategies where applicable, helping fleets in the Permian Basin and West Texas optimize sustainability without sacrificing temperature control.
Installation & Maintenance Tips
Install using non-magnetic mounting hardware and maintain a maximum 19 mm gap between switch and magnet for reliable sensing. Use OEM or equivalent 18 AWG wiring and secure harnesses away from pinch points. Inspect switch alignment and wiring during scheduled maintenance intervals and verify door-switch input settings on the refrigeration unit controller.
Real-World Applications
The Kit Door Switch 400477 is ideal for reefer trailers, refrigerated trucks, and transport refrigeration setups performing frequent loading and unloading. It enhances cargo protection for perishables, pharmaceuticals, and frozen goods by minimizing temperature excursions during door-open events. Available for installation and service in Amarillo, Lubbock, Odessa, and throughout West Texas.
View all Thermo King PartsBacked by Thermo King’s engineering and supported by certified technicians at West Texas Thermo King, this component delivers lasting performance and uptime assurance for fleet operations.
For product verification or service assistance, call (806) 376-5837.
For current warranty eligibility or OEM replacement coverage, please contact us for warranty information or call the service department to confirm specific coverage.
Frequently Asked Questions
Q: Is the Kit Door Switch 400477 compatible with Smart Reefer SR-4 controllers?
A: Yes. The switch provides a door-status input compatible with Smart Reefer controllers; confirm controller input configuration during installation.
Q: What wiring is required for reliable operation?
A: Use a 3-wire harness with 18 AWG minimum and follow color coding for power, ground, and output to ensure correct integration with Thermo King units.
Q: Can this door switch be retrofit on existing reefer trailers?
A: Yes. The low-profile magnetic design mounts to swing-out and roll-up doors and fits common retrofit applications; verify mounting surface and gap requirements before installation.
Related Resources
Ask about fleet-wide parts programs through West Texas Thermo King.
Produced by a certified Thermo King dealership, West Texas Thermo King | a Division of PEAK Industrial. Servicing fleets across Amarillo, Lubbock, and Odessa.
Official OEM Thermo King parts catalog entry for the Kit Door Switch 400477, verified by PEAK Thermo King and West Texas Thermo King Texas, Utah, Wyoming, Washington, Oregon, serving all of the USA.
Built for Performance: The Thermo King Kit Door Switch 400477 supports Thermo King refrigeration system integration and delivers reliable door-status control for reefer trailers and transport refrigeration applications. Engineered for fleets that demand uptime and precise temperature control, this door switch assembly helps protect loads and improve fuel-efficient cooling across regional and long-haul operations.
Key Features & Customer Benefits
- Automatic Unit Control – Stops refrigeration unit runtime when doors open to reduce fuel consumption and maintenance hours.
- Weatherproof Construction – Sealed switch and magnet assembly withstands trailer environments for consistent reliability.
- 3‑Wire Compatibility – Integrates with Thermo King control inputs (use 18 AWG or better harness) to support accurate door-status reporting.
- Low‑Profile Magnetic Mount – Minimizes snag risk and fits swing-out or roll-up doors for seamless retrofit and OEM installs.
- Improved Temperature Protection – Limits heat ingress during loading to preserve cold chains for temperature-sensitive cargo.
- Fleet ROI – Reduces unnecessary run time on Smart Reefer and Diesel Direct Electric units, supporting lower operational costs and extended service intervals.
Product Details
| Part Number | 400477 |
| Function | Magnetic door switch assembly for automatic refrigeration unit control and door-status sensing |
| Construction | Weatherproof, low-profile switch and magnet; solid-state sensing electronics |
| Harness | 3-wire recommended (RED = power, BLACK = ground, WHITE = output); 18 AWG minimum |
| Mounting | Non-magnetic mounting hardware; maximum gap 19 mm (0.75 in.) between switch and magnet |
| Compatibility | Thermo King refrigeration units and reefer trailers that accept door-switch inputs; consult service manual for exact fitment |
Efficiency & Sustainability
This door switch supports fuel-efficient cooling by reducing unnecessary run time on Thermo King units, contributing to lower emissions and operating costs. It integrates with advanced controls such as Smart Reefer SR-4 and complements CARB Evergreen compliance strategies where applicable, helping fleets in the Permian Basin and West Texas optimize sustainability without sacrificing temperature control.
Installation & Maintenance Tips
Install using non-magnetic mounting hardware and maintain a maximum 19 mm gap between switch and magnet for reliable sensing. Use OEM or equivalent 18 AWG wiring and secure harnesses away from pinch points. Inspect switch alignment and wiring during scheduled maintenance intervals and verify door-switch input settings on the refrigeration unit controller.
Real-World Applications
The Kit Door Switch 400477 is ideal for reefer trailers, refrigerated trucks, and transport refrigeration setups performing frequent loading and unloading. It enhances cargo protection for perishables, pharmaceuticals, and frozen goods by minimizing temperature excursions during door-open events. Available for installation and service in Amarillo, Lubbock, Odessa, and throughout West Texas.
View all Thermo King PartsBacked by Thermo King’s engineering and supported by certified technicians at West Texas Thermo King, this component delivers lasting performance and uptime assurance for fleet operations.
For product verification or service assistance, call (806) 376-5837.
For current warranty eligibility or OEM replacement coverage, please contact us for warranty information or call the service department to confirm specific coverage.
Frequently Asked Questions
Q: Is the Kit Door Switch 400477 compatible with Smart Reefer SR-4 controllers?
A: Yes. The switch provides a door-status input compatible with Smart Reefer controllers; confirm controller input configuration during installation.
Q: What wiring is required for reliable operation?
A: Use a 3-wire harness with 18 AWG minimum and follow color coding for power, ground, and output to ensure correct integration with Thermo King units.
Q: Can this door switch be retrofit on existing reefer trailers?
A: Yes. The low-profile magnetic design mounts to swing-out and roll-up doors and fits common retrofit applications; verify mounting surface and gap requirements before installation.
Related Resources
Ask about fleet-wide parts programs through West Texas Thermo King.
Produced by a certified Thermo King dealership, West Texas Thermo King | a Division of PEAK Industrial. Servicing fleets across Amarillo, Lubbock, and Odessa.