National 157 running warm

This guide covers National 157 running warm. Refrigeration and temperature drift troubleshooting.

• Clean condenser coils and verify fan operation.
• Check door gasket seal and airflow clearance.
• Verify temperature probe placement and setpoints.
• Inspect compressor relay and capacitor for faults.

• Perform a controlled test after each adjustment.
• Document the changes and results for future reference.
• If the issue persists, swap with a known-good component.

• Clean components during each service visit.
• Log repeat faults to identify wear patterns.
• Keep spare parts for legacy models on the truck.

• You have repeated failures after controlled testing.
• Safety or electrical issues are suspected.
• You need model-specific parts or OEM guidance.

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