1. Diagnosis:
* Symptom: Before you dive in, precisely define the problem. Does the key turn freely but the ignition doesn't respond? Does the key only turn partway? Is there resistance? Understanding the specific malfunction helps determine the cause.
* Visual Inspection (Easy First Step): With the key removed, carefully observe the area around the ignition switch. Look for anything obviously broken or dislodged. You may be able to see the linkage mechanism itself – a small rod or cable – from the steering column opening. A flashlight will help.
* Key Stuck? If your key is stuck, avoid excessive force! Use penetrating oil (like PB Blaster) and gently work the key back and forth. A stuck key is often a symptom of a separate problem (binding in the cylinder, worn tumbler, etc.), rather than a linkage issue.
2. Accessing the Linkage:
* Steering Column Cover Removal: This is usually the most difficult part. You'll need to remove the lower steering column cover. This often involves removing screws and possibly some plastic clips. Consult a repair manual specific to your 1995 Mercury Sable for precise instructions. These vary slightly by model and trim level.
* Wiring Harness: Be extremely careful near the wiring harness behind the steering column. Do not pull or damage any wires.
3. Repairing the Linkage:
* Identify the Broken Part: Once you have access, inspect the linkage. Common problems include:
* Broken Rod/Cable: The linkage rod or cable might be broken, bent, or disconnected.
* Loose or Disconnected Connector: The rod or cable may have come loose from its connection points on the lock cylinder or ignition switch.
* Worn Bushings or Pivot Points: These wear over time, leading to sloppy movement and failure.
* Repair Options:
* Re-connect: If it's just disconnected, carefully reconnect the linkage components.
* Replace Broken Rod/Cable: This might require a new linkage assembly (often sold as a unit). Finding this part might require a trip to a salvage yard or a specialized auto parts store.
* Repair or Replace Worn Bushings: This is more challenging and might require specific tools and knowledge.
4. Reassembly:
* Carefully reinstall the steering column cover, ensuring all screws and clips are secure.
* Test the ignition switch to confirm the repair.
Important Considerations:
* Repair Manual: A repair manual specific to your 1995 Mercury Sable is highly recommended. It will provide detailed diagrams and instructions for removing the steering column cover and accessing the linkage.
* Safety: Work carefully and avoid damaging any wiring or other components.
* Professional Help: If you're uncomfortable working on your car's steering column, it's best to seek professional assistance from a qualified mechanic. This is a critical area of the vehicle, and improper repair can lead to further damage or safety hazards.
* Ignition Switch Replacement: In some cases, replacing the entire ignition switch assembly may be necessary, especially if the switch itself is faulty. This is often a better long-term solution than just repairing the linkage.
Remember to always disconnect the negative battery terminal before beginning any work on your car's electrical system. Take photos as you disassemble to aid in reassembly. If you are not mechanically inclined, professional assistance is strongly advised.
