35
Thermo King
Critical

Check Run Relay Circuit

Failure detected in the run relay circuit, preventing unit operation.

Possible causes

  • Defective Run Relay
  • Blown fuse in the control circuit
  • Interface board failure
  • Loose terminals in the relay socket

Recommended actions

  • Replace the run relay for testing
  • Verify control system fuses
  • Inspect connections on the main board
  • Test signal wiring continuity

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