Here's a breakdown of troubleshooting and potential fixes, starting with the simplest:
1. Check the Obvious:
* Debris: Check the door track (both upper and lower) for leaves, dirt, mud, or anything else that might be obstructing the rollers. Clean it thoroughly with a brush and compressed air (if available), or a stiff-bristled brush and vacuum cleaner.
* Frozen Mechanisms: In cold climates, ice or frozen debris can be a significant culprit. Try using de-icer spray (designed for car locks and mechanisms) on the tracks and rollers. Let it sit for a while before attempting to open the door.
2. Examine the Rollers:
* Worn or Damaged Rollers: The rollers on the sliding door can wear down over time, causing binding. Inspect the rollers closely. Are they damaged, cracked, or excessively worn? If so, they'll need to be replaced. These are usually available from auto parts stores.
* Roller Alignment: Ensure the rollers are properly seated in the track. Sometimes, they can become dislodged or misaligned, hindering movement. Gently try to reposition them if they're out of place.
3. Investigate the Latch Mechanism:
* Latch Stuck: The latch mechanism itself might be jammed or malfunctioning. Try gently working the latch handle back and forth. If you can see anything obstructing it, remove it carefully. If it's consistently sticking, you might need to lubricate it (use a silicone-based spray lubricant, *avoiding WD-40*).
* Broken Latch Components: The latch mechanism can break or become misaligned. A visual inspection might reveal a broken spring or other damaged components. Replacement parts might be necessary in this case.
4. Check the Track:
* Bent or Damaged Track: The door track itself can become bent or damaged, preventing smooth operation. Inspect it carefully for any bends or deformations. Minor bends might be gently corrected with pliers or a hammer (use caution!), but significant damage likely requires track replacement.
5. Investigate the Door itself:
* Door Binding: The door itself might be slightly warped or binding against the frame. Check if the door is rubbing against any part of the body.
* Window interference: If the window is up, it could be interfering with the door. Try lowering the window.
6. When all else fails:
* Professional Help: If you've exhausted all other options, it's time to consult a mechanic or body shop specializing in older vehicles. They have the experience and tools to diagnose and repair more complex issues.
Important Notes:
* Lubrication: Use a silicone-based lubricant sparingly. Avoid using WD-40, as it's a solvent and can attract dirt, eventually leading to more problems.
* Parts: Finding replacement parts for a 1991 Aerostar might require some searching, as many parts are discontinued. Online auto parts retailers or salvage yards can be good sources.
* Safety: Be careful when working on the door. Avoid getting your fingers pinched or injured by moving parts.
Remember to take your time and carefully examine each component. Often, a simple cleaning or minor adjustment can solve the problem. Good luck!
