Ignition System:
* Ignition Switch: This is a common failure point. It might be failing to send power to the starter, even if the battery and starter are good. This often manifests as a complete lack of any cranking sound.
* Ignition Coil(s): If the coil isn't firing, the engine won't start. This would result in no spark at the spark plugs.
* Distributor (if applicable): Older Windstars might have distributors. A faulty distributor cap, rotor, or internal components can prevent the spark from reaching the plugs. (Less likely on newer models)
* Camshaft Position Sensor (CMP) or Crankshaft Position Sensor (CKP): These sensors tell the computer the engine's position. A faulty sensor will prevent the computer from sending the signal to start. The engine may crank but not fire.
* Spark Plugs and Wires: While you might think a new starter rules this out, worn or fouled spark plugs or damaged wires can prevent ignition. Check for cracks or corrosion.
* Ignition Control Module (ICM): This module controls the ignition system. A faulty ICM can prevent the engine from firing.
Fuel System:
* Fuel Pump: The fuel pump might be failing to deliver fuel to the engine. You might hear a faint whirring sound from the fuel pump when you turn the key if it's struggling.
* Fuel Filter: A clogged fuel filter can restrict fuel flow.
* Fuel Injectors: Clogged or faulty injectors could prevent fuel from being sprayed into the cylinders.
* Fuel Pressure Regulator: This regulates fuel pressure. A faulty regulator can cause low fuel pressure.
Other Possibilities:
* Neutral Safety Switch: This switch prevents starting unless the transmission is in Park or Neutral. A faulty switch will prevent the starter from engaging.
* Security System: Some Windstars have anti-theft systems. A malfunctioning system could prevent starting.
* Computer/PCM Issues: Problems with the Powertrain Control Module (PCM) can cause a wide range of starting issues.
* Wiring Problems: A loose, corroded, or damaged wire anywhere in the starting or ignition circuit can prevent the vehicle from starting. This requires careful inspection.
* Bad Ground: A poor connection to the engine block or battery ground can hinder the electrical flow necessary to start the car.
Troubleshooting Steps:
1. Check for any error codes: Use an OBD-II scanner to check for diagnostic trouble codes (DTCs). This will often point directly to the problem.
2. Listen Carefully: When you turn the key, are there *any* sounds? A clicking sound could indicate a relay or solenoid problem. A whirring sound might be the fuel pump.
3. Check Fuel Pressure: If you have the tools, check fuel pressure to see if the fuel system is delivering fuel.
4. Test Spark: Check for spark at the spark plugs.
5. Inspect Wiring: Look for any signs of damage, corrosion, or loose connections in the wiring harness, especially around the starter, ignition switch, and fuel pump.
6. Check Fuses and Relays: Make sure all relevant fuses and relays are good.
If you're not comfortable performing these checks yourself, it's best to take your Windstar to a qualified mechanic for diagnosis. They have the tools and expertise to pinpoint the problem more efficiently.
