* Latch Mechanism Issues: This is the most likely culprit. The latch itself might be broken, jammed, or misaligned. The mechanism could be worn out from years of use, or something might be obstructing it.
* Trunk Release Cable: The cable that connects the interior and exterior trunk releases could be broken, frayed, or disconnected. This would prevent you from opening or closing the trunk reliably.
* Electrical Problems: If your DeVille has a power trunk release, a faulty switch, wiring harness, or actuator motor could prevent proper closing. This is less likely to cause a complete inability to close, but might cause intermittent problems or slow/weak closing.
* Broken or Bent Trunk Strut(s): The gas struts (or shocks) that assist in holding the trunk open might be worn out or damaged. While this won't directly *prevent* closing, a weak or broken strut could cause the trunk to fall unexpectedly or make it difficult to close fully and securely.
* Obstructions: Something might be blocking the trunk from closing properly. Check inside the trunk for anything interfering with the latch mechanism.
* Misalignment: The trunk lid itself might be slightly misaligned. This could be due to a previous accident or simply wear and tear.
Troubleshooting Steps:
1. Visual Inspection: Carefully examine the latch mechanism, both inside the trunk and on the trunk lid itself. Look for any obvious damage, obstructions, or misalignment. Check the trunk release cable for damage.
2. Manual Release: Try using the key to unlock the trunk. If it opens that way but not with the interior or exterior release buttons, the issue likely lies with the release cable or electrical system.
3. Check for Obstructions: Thoroughly check inside the trunk for any items that might be preventing the trunk from closing fully.
4. Test the Trunk Release: Try all methods of releasing the trunk (interior button, exterior button, key). Note if any method works better than others.
5. Listen for Sounds: When attempting to close the trunk, listen closely for any unusual sounds (grinding, clicking, etc.). This can provide clues about the source of the problem.
If you've checked these things and are still unable to close the trunk, you might need to consult a mechanic or auto repair shop. They'll have the tools and expertise to diagnose and repair the problem properly.
