Things You'll Need
Replacement 10A fuse (slot 24)
If the gauges on the instrument cluster of your Chevrolet TrailBlazer are not functioning properly, there could be three possible causes: the gauges' fuse has blown out, the wiring connectors are loose, or the gauges themselves are bad. Remedying any of those situations is fairly simple and should only take half an hour to complete. If the gauges are bad, you will need to purchase a new instrument cluster to replace the faulty one which can be fairly expensive.
Turn your TrailBlazer's engine off. Pull on the hood release lever to the left of and below the steering wheel in order to open the hood. Secure it open with the prop rod.
Remove the cover from the TrailBlazer's fuse block in the engine compartment. Locate the fuse in slot 24. This is the instrument cluster fuse.
Use a fuse puller tool to remove the fuse from the fuse block. Install a new 10A fuse into the TrailBlazer's fuse block.
Reattach the fuse block's cover and close the hood. If the gauges are still malfunctioning, the issue may be the wiring.
Remove the three fastening screws from underneath the dashboard trim above the instrument cluster with a Phillips screwdriver. Pull the dashboard trim off. If necessary, lower the steering wheel down to its lowest point.
Remove the four fastening screws on the instrument cluster itself using a Phillips screwdriver. Pull the cluster towards you.
Reach behind the cluster to access the gauge wires. Make sure all of the wires are properly connected to the instrument cluster. If not, pull them off and connect them, making sure that all of the wires "snap" into place. If the gauges are still malfunctioning, the issue may be with the instrument cluster itself.
Disconnect all three of the wires at the rear of the instrument cluster and pull the cluster out of the TrailBlazer. Install a replacement cluster and attach all three wires to the new cluster.
Reinstall the four cluster screws and the dash trim. Reattach the three screws to the dash trim.
For an added safety measure, you should disconnect the battery beforehand.