SFN-20231011C_Replace the blower motor assembly

TICO Document #: SFN-20231011C (formerly TES-216)

Complication: The heater blower motor fan is failing due to a defective material

Description of Procedure: Replace the blower motor assembly

Units Affected: Red DOT units installed at TICO from 1/1/18 to 8/20/18

Parts Required: Red DOT GFN Blower motor, 920420-1, (QTY) 1

Planned Labor: 3 Hours

Instructions:

1. Park the vehicle on a flat surface, apply a parking brake, and chock wheels. If your company utilizes a “Lock Out, Tag Out” policy, you should employ it during this procedure.

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2. Remove the left side outer cab access panel, as shown in Figure #1. Be sure to retain the hardware for the re-installation.

3. Remove the HVAC ducting hoses by loosening the retaining clamps from the unit plenum in the locations shown in Figure #2

4. Label or mark each hose to the plenum port so the hoses can be reinstalled in the correct location.

5. On the inside of the cab, remove the interior cab trim panel shown in Figure #3. Retain the hardware for re-installation.

6. Remove the heater access panel, as shown in Figure #4. It may be necessary to loosen the fuse panel to remove the heater access panel, as shown in Figure #5. Retain the hardware for re-installation.

7. Remove the additional HVAC ducting hoses by loosening the retaining clamps from the top of the plenum. See Figure #6.

8. Label or mark each hose to the plenum port so the hoses can be reinstalled in the correct location.

   

9. Remove (6) screws securing the blower housing to the core housing & (2) screws that attach the water valve bracket to the blower housing (2a). See Figure #7.

10. Loosen (2) ¼-20 wing nuts that secure filter cover (2b). See Figure #8.

11. Slide the filter cover past the end of the flange on blower housing to allow housing to be lifted off core housing enough to disconnect wires from the thermostat. See Figure #9.

    During the removal of blower housing, the water valve support bracket will need to be moved out of the way for flange on blower housing to pass.

    

12. Remove (4) screws that attach the motor blower to the blower housing. Retain screws for re-installation. See Figure #10.

    

13. Unplug 90° flag terminals from the resistor pack and black ground wire on blower and remove existing motor blower from blower housing. See Figure #11.

14. Obtain the replacement GFN blower motor and prepare for installation.

    

15. Attach (3) 90° flag terminals and black ground wire onto the new GFN blower. Connections are color-coded from left to right, Purple - Yellow - Orange, as shown in Figure #12

    

16. Assemble the new GFN motor blower into the blower housing using (4) M4 x .7 Pan head Phillips screws. Torque to 12 in-lbs. See Figure #13.

    

17. Reconnect wires to thermostat. See Figure #14.

    

18. Place blower housing back onto core housing and secure with (6) 10-16 Crimptite screws. Torque to 40-45 in-lbs. Make sure that thermostat wires don’t get damaged by being pinched under flange. See Figure #15.

    

19. Secure the water valve support bracket to the blower housing using (2) 10-16 Crimptite screws. Torque to 40-50 in-lbs. See Figure #16.

    

20. Slide the filter cover back over the flange on the blower housing and against the filter, then tighten ¼-20 wing nuts. See Figure #17.

    

21. Reinstall HVAC ducting hoses and tighten the retaining clamps from the unit plenum in the locations shown in Figures #18 & #19.

22. Reinstall the heater access panel with the associated hardware as shown in Figure #20.

23. Tighten the fuse panel screws if previously loosened.

    

24. Reinstall the cab interior trim panel with the associated hardware shown in Figure #21.

    

25. Reinstall the left side outer cab access panel with the associated hardware as shown in Figure #22.

    

26. Remove “Lock Out, Tag Out” plaque.

27. Return vehicle to service.