GM Service Manual Online
For 1990-2009 cars only

    Object Number: 421407  Size: SH
  1. Slide the signal switch housing assembly (2) onto the steering shaft assembly.
  2. Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  3. Install the 2 washer head screws (1) into the signal switch housing assembly (2).
  4. Tighten
    Tighten the washer head screws to 3.5 N·m (31 lb in).


    Object Number: 421408  Size: SH
  5. Insert the horn contact spring and the horn contact (2) into the signal switch housing assembly (1).
  6. Insert the horn contact plunger into the signal switch housing assembly (1) and turn to lock in place.

  7. Object Number: 421399  Size: SH
  8. Insert the turn signal and multifunction switch assembly (1) into the signal switch housing assembly until the tabs lock in place.
  9. Connect the connectors on the turn signal and multifunction switch assembly (1), if needed.

  10. Object Number: 421398  Size: SH
  11. Insert the windshield wiper and washer switch assembly (1) into the signal switch housing assembly.
  12. Connect the connectors on the windshield wiper and washer switch assembly (1), if needed.
  13. Install the turn signal cancel cam and upper bearing inner race. Refer to Turn Signal Cancel Cam and Upper Bearing Inner Race - Assemble - Off Vehicle .
  14. Enable the inflatable restraint steering wheel module. Refer to Enabling the SIR System in SIR.