1. Check the Obvious:
* Wiper Blades: Make sure both wiper blades are securely attached. A loose or improperly installed blade can prevent movement. Try swapping blades to eliminate a faulty blade as the cause.
* Debris: Inspect the wiper arms and linkage for any debris (leaves, ice, etc.) that might be obstructing movement. Clear away any obstructions.
2. Inspect the Linkage:
This is the most likely culprit. The wipers are connected by a series of arms and pivots. One arm's failure to move means a problem within this linkage.
* Access the Linkage: You'll need to access the wiper linkage mechanism. This usually involves removing the cowl (the plastic cover under the windshield wipers). Consult your Ford Windstar's repair manual or search online for a video showing how to remove the cowl for your specific year.
* Visual Inspection: Carefully examine the linkage for:
* Broken or bent arms: Look for any obvious signs of damage.
* Loose or disconnected components: Check all the joints and connections for looseness or disconnection.
* Seized pivot points: Try to gently move each joint by hand. If one is stiff or doesn't move freely, it's likely seized and needs lubrication or replacement.
* Lubrication: If the joints are stiff but not broken, apply a small amount of silicone-based lubricant (not WD-40, as it can attract dirt) to the pivot points. Work the linkage gently to distribute the lubricant.
3. Motor and Transmission:
While less likely given only one wiper is failing, a problem in the wiper motor or transmission could cause this. However, a failing motor would typically affect *both* wipers.
* Check the Motor (Less Likely): Accessing the motor might require more extensive disassembly. If you've checked the linkage and found nothing, this becomes a possibility but should only be pursued if you're comfortable with more involved car repairs.
4. Fuse (Least Likely):
A blown fuse would usually affect both wipers. Check your owner's manual to locate the wiper fuse and test it with a multimeter. Replacing it if blown is straightforward.
Important Considerations:
* Repair Manual: A repair manual specific to your year and model Ford Windstar is invaluable. It will provide detailed diagrams and instructions for accessing and repairing the wiper system.
* Safety: Disconnect the battery's negative terminal before working on the wiper system to prevent accidental short circuits.
* Professional Help: If you're not comfortable with automotive repairs, it's best to take your Windstar to a qualified mechanic. Improper repair could lead to further damage.
By systematically checking these points, you should be able to identify the cause of your single-wiper malfunction. Remember to always prioritize safety and consult a professional if you're unsure about any step.
