GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

  1. Disconnect the battery ground (negative) cable. Refer to Battery Negative Cable Disconnection and Connection .
  2. in Engine Electrical.

  3. Remove the battery positive cable from the top of the underhood accessory wiring junction block. Refer to Battery Cable Replacement in Engine Electrical.
  4. Remove the top cover of the underhood accessory wiring junction block by unscrewing the center knob if you access the fuses.

  5. Object Number: 321480  Size: SH
  6. Release the four retainer tabs in order to remove the underhood accessory wiring junction block from the junction block bracket.

  7. Object Number: 321477  Size: SH
  8. Disconnect the top three instrument panel harness connectors.
  9. Remove the bolt/screw from the three harnesses.
  10. Disconnect the three harnesses, starting at the top.

  11. Object Number: 321473  Size: SH
  12. Disconnect the engine harness.

  13. Object Number: 321469  Size: SH
  14. Disconnect the instrument panel harness.

  15. Object Number: 321458  Size: SH
  16. Disconnect the forward lamp harness.
  17. Position all harnesses from junction block bracket.
  18. Release the positive battery cable from the junction block bracket retainers.
  19. Remove the nut from the top of the junction block bracket retainers.

  20. Object Number: 321442  Size: SH
  21. Lift the junction block bracket up and out from the shock tower.

Installation Procedure


    Object Number: 321442  Size: SH
  1. Insert the lower tab of the junction block bracket into the shock tower slot.
  2. Insert the top of the junction block bracket over the stud on the shock tower.
  3. 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.

  4. Install the nut to the stud on the top of the junction block bracket.
  5. Tighten
    Tighten the junction block bracket nut to 3 N·m (27 lb in).

  6. Position the positive battery cable to the junction block bracket and secure using the retainers.
  7. Starting at the bottom, install three harnesses into the junction block.

  8. Object Number: 321458  Size: SH
  9. Connect the forward lamp harness.

  10. Object Number: 321469  Size: SH
  11. Connect the instrument panel harness.

  12. Object Number: 321473  Size: SH
  13. Connect the engine harness.
  14. Install the bolt/screw to the three harnesses.
  15. Tighten
    Tighten the junction block harnesses bolt/screw to 7 N·m (62 lb in).


    Object Number: 321477  Size: SH
  16. Install the top three instrument panel harness connectors.
  17. Position the junction block into the junction block bracket.

  18. Object Number: 321480  Size: SH
  19. Snap in the junction retainers into until fully seated.
  20. Replace the top cover and tighten using the center knob if fuses were accessed.
  21. Install the battery positive cable to the top of the underhood accessory wiring junction block. Refer to Battery Cable Replacement in Engine Electrical.
  22. Connect the battery ground (negative) cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.