WOMS
C code chassis Medium severity

C1779 Blower Switch Failure

The OBD2 code C1779 indicates a malfunction in the blower switch, which controls the operation of the vehicle's blower motor for heating and air conditioning

Definition

The OBD2 code C1779 indicates a malfunction in the blower switch, which controls the operation of the vehicle's blower motor for heating and air conditioning

Common causes

  • Faulty blower switch
  • Wiring issues or shorts
  • Poor electrical connections
  • Blower motor failure
  • Blower motor resistor failure
  • Faulty HVAC control module
  • Corroded connectors or terminals
  • Software issues in the vehicle's control system

Common misdiagnoses

  • Blower Motor Failure
  • Blower Resistor Failure
  • HVAC Control Module Failure
  • Wiring Issues or Shorts
  • Fuse Failure
  • Climate Control Module Malfunction
  • Grounding Issues

Troubleshooting steps

  1. 1. Check the Blower Motor

  2. 2. Ensure that the blower motor is functioning properly. You can do this by applying direct power to the motor to see if it operates

  3. 3. Inspect the Blower Motor Resistor

  4. 4. The blower motor resistor controls the speed of the blower motor. If it is faulty, it may cause the blower to not operate correctly. Test the resistor for continuity and replace it if necessary

  5. 5. Examine the Blower Switch

  6. 6. The blower switch itself may be faulty. Check for proper operation and continuity in the switch. If the switch is defective, it will need to be replaced

  7. 7. Check Wiring and Connectors

  8. 8. Inspect the wiring and connectors related to the blower motor and switch for any signs of damage, corrosion, or loose connections. Repair or replace any damaged components

  9. 9. Test the HVAC Control Module

  10. 10. If the vehicle is equipped with an HVAC control module, it may be malfunctioning. Use a scan tool to check for any additional codes and perform tests as needed

  11. 11. Inspect Fuses

  12. 12. Check the fuses related to the blower motor circuit. A blown fuse can prevent the blower from operating. Replace any blown fuses

  13. 13. Scan for Additional Codes

  14. 14. Use an OBD-II scanner to check for any other related trouble codes that may provide more insight into the issue

  15. 15. Perform a Visual Inspection

  16. 16. Look for any signs of physical damage or wear in the blower motor assembly, wiring harness, and connectors

  17. 17. Consult Wiring Diagrams

  18. 18. Refer to the vehicle’s service manual for wiring diagrams to understand the circuit better and identify any potential issues

  19. 19. Clear Codes and Test Drive

  20. 20. After performing repairs, clear the trouble codes and take the vehicle for a test drive to see if the code returns. If these steps do not resolve the issue, it may be necessary to consult a professional mechanic for further diagnosis and repair