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Heater Main Relay Circuit

  1. Check heater main relay. See appropriate AUTOMATIC A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING. If heater main relay is okay, go to next step. Replace heater main relay as necessary. Retest system operation.
  2. Check circuits for faults between heater main relay and body control ECU No. 1. See WIRING DIAGRAMS . Repair or replace as necessary. If circuits are okay, go to next test listed in appropriate SYMPTOM DIAGNOSIS table under TROUBLE SHOOTING .
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