Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2006 Hummer H3 L5-3.5LFACTORY OEM SERVICE PROCEDURE
Fuse Block: Service and Repair
UNDERHOOD ELECTRICAL CENTER OR JUNCTION BLOCK REPLACEMENT
REMOVAL PROCEDURE
1. Open and support the hood.
2. Disconnect the negative battery cable.
3. Remove the cover (1) from the base (5) of the accessory wiring junction block assembly.
4. Remove the positive battery cable nut (2) and disconnect the cable (3) from the positive terminal stud.
5. Release the 2 locking tabs from the base side as indicated by the arrows of the electrical center (1), as shown.
6. Carefully lift at each side of the underhood accessory wiring junction block assembly in order to release the underhood accessory wiring junction block assembly from the 3 main body harness connectors (1) and exposing the lower connectors.
7. Remove the underhood accessory wiring junction block assembly from the vehicle.
8. Use the hook tool to pull the connector (1) upward in order to secure the connectors into the base.
IMPORTANT: Using a hook-type tool, as shown, re-stage all 3 lower harness connectors into the lower base prior to installing the new underhood accessory wiring junction block assembly.
INSTALLATION PROCEDURE
1. Verify that all 3 connectors (1) are secured to the base by applying light downward pressure to each connector and verifying the tabs are locked (2) on each side of the connector.
2. Position the new underhood accessory wiring junction block assembly over the top of the base and align the locator pins to the underhood accessory wiring junction block assembly base.
3. Once aligned, apply downward pressure to the new underhood accessory wiring junction block assembly in order to secure the top half to the base.
4. Inspect the 2 outer locking tabs to ensure the new underhood accessory wiring junction block assembly is locked into the lower base (2).
5. Install the positive battery cable (3) over the stud and install the retaining nut (2).
NOTE: Refer to Fastener Notice in Service Precautions.
Tighten the nut to 10 N.m (89 lb in).
6. Install the underhood electrical center cover (1) to the electrical center base (5).
7. Connect the negative battery cable.
8. Close the hood.
Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.