There are a few possibilities, and pinpointing the exact method depends on how the automatic locking system is implemented in your specific vehicle:
* Vacuum System (Most Likely): Many cars from this era used a vacuum system. The system relies on a vacuum pump, lines running throughout the car, and actuators at each door. To disable the automatic locking:
* Locate the vacuum pump: This is usually under the hood. You might find a diagram in your owner's manual.
* Trace the vacuum lines: Follow the vacuum lines from the pump to the door lock actuators. These lines are usually thin and made of rubber or plastic.
* Disconnect the lines: You could disconnect the lines at the pump to disable the entire system. A more targeted approach would be to disconnect the lines leading to the individual door lock actuators. Be careful not to damage the lines.
* Alternative (potentially safer): Instead of disconnecting lines, you could carefully pinch or block individual lines using appropriately sized clamps or plugs. This allows you to easily restore the system later.
* Electrical System (Less Likely, but Possible): Some cars might have used an electrical system instead of vacuum. This would involve a control module, wiring harness, and electric actuators at each door. Disabling this is much more complex and would require:
* Identifying the control module: This might be located in the interior fuse box or under the dash.
* Tracing the wiring: This requires skill with a wiring diagram and multimeter to identify the wires controlling the automatic locking. Improper disconnection can damage your car's electrical system.
* Disconnecting the wiring: Carefully disconnect the relevant wires at the control module or actuators, preferably using appropriate disconnects rather than cutting wires.
Important Considerations and Warnings:
* Safety First: Disconnect the negative battery terminal before starting any electrical work.
* Wiring Diagram: Obtaining a wiring diagram for your specific 1991 Buick Regal Gran Sport is highly recommended. This will help you identify the correct components and wiring. You can find these diagrams online from various automotive repair resources or at a parts store.
* Professional Help: If you are not comfortable working with automotive electrical or vacuum systems, it's best to consult a qualified mechanic. Incorrectly disconnecting or manipulating these systems could damage your car's electrical system, lead to safety hazards, or even create problems with your insurance.
* Alternative Solutions: Before disconnecting anything, consider if there's a setting within your car's system (perhaps a fuse, a switch, or a setting in the BCM Body Control Module) that allows you to disable the automatic locking. Check your owner's manual.
Disconnecting the auto-locking system is a potentially involved task. Proceed with caution and, if uncertain, seek professional assistance. Improper work could cause significant damage.
