GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 HUMMER 🢒 2009 🢒 H2 🢒 Power and Signal Distribution 🢒 Wiring Systems and Power Management 🢒 Underhood Electrical Center or Junction Block Replacement

Removal Procedure
  1. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection.

    2. Object Number: 400853 Size: SH
  2. Remove the left fender upper brace.

    3. Object Number: 749941 Size: SH
  3. Remove the electrical center brace cover assemble by lifting the cover (3) outwards to clear the tabs.
  4. Remove all fuses and relays.

    5. Object Number: 749942 Size: SH
  5. Push on the tab (3) so that the electrical center can be rotated on the studs located at (2).
  6. Remove all connectors by removing the bolt (1) for each connector.
  7. Disconnect all connectors from the electrical center block.

    8. Object Number: 749945 Size: SH
  8. Push on the tabs (2) in order to lift the electrical center (1) out of the housing.

    9. Object Number: 747706 Size: SH
  9. To replace the engine electrical center bracket remove the 4 retaining bolts (1).
  10. Remove the engine electrical center bracket assembly from the fender.

Installation Procedure

    Object Number: 747706 Size: SH
  1. Install the engine electrical center bracket assembly to the front fender.

    2. Caution: Refer to Fastener Caution in the Preface section.

  2. Install the 4 retaining bolts (1).

    3. Tighten
    Tighten the 4 retaining bolts (1) to 9 N·m (80 lb in).


    Object Number: 749945 Size: SH
  3. Align the electrical center block (1) stubs in the slots so that the tabs (2) retains it in place.

    4. Object Number: 749942 Size: SH
  4. Connect the wire connectors to the lower portion of the electrical center block.
  5. Connect the wire connectors with the bolts to the electrical center block.

    6. Tighten
    Tighten all connector bolts (1) to 9 N·m (80 lb in).

  6. Ensure all wire connectors are securely connected.
  7. Set the electrical center block in its resting position till the tabs (3) locks in place.

    8. Object Number: 749941 Size: SH
  8. Install the lower part of the cover (1).
  9. With the cover (2) off, use the fuse location information to install all fuses and relays.
  10. Install the cover.

    11. Object Number: 400853 Size: SH
  11. Install the fender upper brace.
  12. Install the 4 fender upper brace bolts.

    13. Tighten
    Tighten the 4 retaining bolts to 25 N·m (18 lb ft).

  13. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection.
  14. Start vehicle and ensure all components function properly.