Rear Electrical Center or Junction Block Replacement

Rear Electrical Center or Junction Block Replacement

Removal Procedure

Warning: Refer to Battery Disconnect Warning (Battery Disconnect Warning).
1. Disconnect the battery negative cable. Refer to Battery Negative Cable Disconnection and Connection (Service and Repair).
2. If replacing the rear electrical center on a GMC Envoy XL, remove the left second row seat. Refer to Rear Seat Replacement (Rear Seat Replacement).




3. If replacing the rear electrical center on a Chevrolet TrailBlazer or GMC Envoy, position the left second row seat to a cargo position.
4. Remove the rear electrical center cover.




5. Remove the battery feed terminal nut (2) from the junction block.
6. Remove the body control module (BCM) from the rear electrical center. Refer to Body Control Module Replacement (Removal and Replacement).
7. Fully loosen the 3 bolts (1) that retain the junction block to the electrical connectors.




8. Release the tabs that retain the junction block to the block base.
9. Remove the junction block from the block base.




10. Disconnect the instrument panel harness connector (1) from the junction block.




11. Disconnect the mobile telephone harness connector (1) from the junction block.




12. Disconnect the body wiring harness connector (1) from the junction block.
13. Disconnect the headliner harness connector (2) from the junction block.
14. Disconnect the console harness connector from the junction block.
15. Remove the block base retaining nuts from the floor studs.
16. Remove the block base from the floor panel.

Installation Procedure




1. Install the block base to the floor studs.

Caution: Refer to Fastener Caution (Fastener Caution).

2. Install the block base retaining nuts to the floor studs.

Tighten the block base retaining nuts to 10 Nm (88 lb in).

3. Connect the console harness connector to the block base.
4. Connect the headliner harness connector (2) to the block base.
5. Connect the body wiring harness connector (1) to the block base.




6. Connect the mobile telephone harness connector (1) to the junction block.




7. Connect the instrument panel harness connector (1) to the block base.




8. Install the junction block to the block base.
Ensure that the retaining tabs are fully seated.




9. Install the 3 bolts (1) that retain the junction block to the block base.

Tighten the 3 bolts to 3.5 Nm (31 lb in).

10. Install the BCM to the rear electrical center. Refer to Body Control Module Replacement (Removal and Replacement).
11. Install the battery feed terminal nut (2) to the junction block.

Tighten the battery feed terminal nut to 10 Nm (88 lb in).




12. Install the rear electrical center cover.
13. If replacing the rear electrical center on a Chevrolet TrailBlazer or GMC Envoy, position the left second row seat to a passenger position.
14. If replacing the rear electrical center on a GMC Envoy XL, install the left second row seat. Refer to Rear Seat Replacement (Rear Seat Replacement).
15. Connect the battery negative cable. Refer to Battery Negative Cable Disconnection and Connection (Service and Repair).