1. Diagnose the Problem:
* No lights at all: This points to a blown fuse, a bad ground connection, or a problem with the wiring harness.
* Only one side is out: This suggests a problem with the bulb, the socket, or the wiring on that specific side.
* Intermittent lights: This might be a loose connection, a failing bulb, or corrosion in the wiring.
* Only certain functions are out (brake lights, turn signals, reverse lights): This usually pinpoints a specific bulb or a problem in the associated circuit.
2. Tools and Materials You'll Need:
* Socket set (likely metric): For removing the tail light assembly.
* Screwdrivers (Phillips and flathead): Depending on the type of screws used.
* Test light or multimeter: To check for power at the connections.
* Replacement bulbs: Match the wattage and type of the original bulbs. (Consult your owner's manual or an auto parts store for the correct ones.)
* Electrical tape or connectors: For fixing wire connections if necessary.
* Wrench (if necessary): Some tail light assemblies might have nuts to loosen.
* Gloves: To protect your hands.
* Owner's Manual: This is invaluable for locating diagrams and specifications.
3. Steps to Repair:
* Locate the Tail Light Assembly: On an '89 Silverado, the taillights are usually accessed from the inside of the truck bed. You'll likely need to remove screws or nuts holding the assembly in place.
* Remove the Tail Light Assembly: Carefully remove the screws or nuts securing the taillight assembly. Gently pull the assembly outward. Take note of how the assembly comes apart to reassemble it later.
* Inspect the Bulbs: Check each bulb for damage or breakage. If a bulb is burnt out, replace it with the correct type. Make sure to push the new bulb firmly into the socket.
* Check the Socket: Inspect the bulb socket for corrosion, damage, or loose connections. Clean any corrosion with a wire brush and apply dielectric grease to the contacts to prevent future corrosion. If the socket is damaged, it will need to be replaced.
* Check the Wiring: Examine the wiring harness for loose connections, broken wires, or damaged insulation. If you find any problems, repair them using electrical tape or proper connectors.
* Check the Ground: A poor ground can cause all sorts of lighting issues. Look for the ground wire connected to the tail light assembly (usually a bare metal wire connected to the truck body). Clean the connection and ensure it's making good contact.
* Check the Fuse(s): Locate your fuse box (usually under the hood or inside the cab) and check the fuses related to the taillights. If a fuse is blown, replace it with one of the same amperage rating. If the fuse keeps blowing, there's likely a short circuit somewhere in the wiring.
* Test the Lights: Once you've made the necessary repairs, reassemble the taillight assembly and test all the lights (brake lights, turn signals, reverse lights, running lights).
4. If the Problem Persists:
If you've checked all of the above and the taillights still don't work, it's likely a more serious wiring problem within the vehicle's electrical system. At this point, it's best to consult a qualified auto electrician.
Important Safety Note: Always disconnect the negative battery terminal before working on any electrical components in your vehicle to prevent accidental shocks. If you're uncomfortable performing any of these repairs yourself, it's best to take your truck to a qualified mechanic.
