Here's a breakdown of why:
* Flickering lights: This is a classic symptom of low voltage. The system is struggling to maintain power.
* Odometer, speedometer, power locks failure: These are all electrically powered components. A significant voltage drop prevents them from functioning correctly.
Possible Culprits:
* Alternator: The most likely culprit. A failing alternator isn't charging the battery properly, leading to low voltage. The flickering lights are the battery struggling to compensate.
* Battery: While less likely than the alternator being the primary problem, a weak or failing battery can also contribute to this. It might be unable to hold a charge even if the alternator is working correctly.
* Battery Cables and Connections: Corroded or loose battery terminals (positive and negative) can significantly impact the electrical system's ability to receive and distribute power.
* Grounding Issues: A poor ground connection somewhere in the vehicle's electrical system can cause similar problems. This is harder to diagnose and requires more electrical testing.
* Wiring Harness: Though less probable, damage to the main wiring harness could be causing intermittent connections or shorts. This is typically more likely to cause complete failures than flickering lights.
* Body Control Module (BCM): In some cases, a malfunctioning BCM could also contribute to these issues, but it's less common than the problems listed above.
What to do:
1. Check the battery terminals: Clean and tighten the connections. Corrosion is a common problem.
2. Test the battery voltage: With the engine off, the voltage should be around 12.6 volts. If it's significantly lower, the battery might need replacement.
3. Test the alternator: This requires a multimeter or a visit to an auto parts store. They can usually test the alternator for free. The alternator should be producing around 13.5-14.5 volts when the engine is running.
4. Visual inspection of wiring: Look for any obvious damage to the main wiring harness, particularly near the battery and alternator.
If you're not comfortable doing this yourself, take the Windstar to a mechanic or auto electrician for diagnosis and repair. The problem is likely relatively straightforward to fix once the source (alternator, battery, or connections) is identified.
