* Broken internal mechanism: This is the most likely culprit. The handle might feel loose, not actuate the latch, or simply be broken off.
* Broken exterior handle: The outside handle itself might be cracked or broken.
* Wiring issues (power locks): If your power locks are malfunctioning specifically for that door, the problem might lie in the wiring harness.
Troubleshooting and Repair Steps:
1. Identify the Problem: Is the problem with the interior handle, exterior handle, or both? Does the power lock still work? Does the handle feel loose or solid?
2. Interior Handle:
* Assess Damage: Remove the interior door panel (lots of online tutorials show this for a 1996 Grand Prix; search "1996 Pontiac Grand Prix interior door panel removal"). Once removed, carefully inspect the mechanism. Look for broken plastic parts, disconnected linkages, or a damaged cable.
* Repair or Replace: If a small plastic part is broken, you *might* be able to repair it with epoxy or super glue. However, replacing the entire interior handle assembly is often easier and more reliable. These are readily available online from auto parts stores or junkyards.
* Reassembly: Once you've repaired or replaced the internal mechanism, reassemble the door panel, ensuring all clips and screws are secure.
3. Exterior Handle:
* Assess Damage: If the exterior handle is broken, you'll likely need to replace it. The handle is usually held in place with screws or clips. Accessing these may require removing the interior panel partially or completely.
* Replacement: Locate a replacement exterior handle. Again, online auto parts stores and junkyards are good resources. Installation usually involves reversing the removal process.
4. Power Lock Issues:
* Check Wiring: If only the power lock is failing, inspect the wiring harness connecting to the door. Look for broken wires, loose connections, or corrosion. Repair or replace any damaged wires. You might need a wiring diagram.
* Actuator: The power lock actuator itself may be faulty. This would require removing the interior panel and replacing the actuator.
Important Considerations:
* Door Panel Removal: This is often the most challenging part. There are numerous videos on YouTube showing how to remove the door panel on a 1996 Grand Prix. Search for "1996 Pontiac Grand Prix door panel removal" and carefully follow the instructions. Be gentle to avoid breaking any clips.
* Parts: Finding replacement parts might require visiting a junkyard or ordering online. Always check the part number to ensure compatibility.
* Safety: Disconnect the battery's negative terminal before working on any electrical components.
If you're not comfortable working on your car yourself, it's best to take it to a qualified mechanic. This will save you time and potential frustration.
