* Ignition Switch: The ignition switch itself could be faulty, not sending power to the ignition system when the key is turned. This is a common failure point.
* Wiring: Check all the wiring between the ignition switch, the ignition module, the coil, and the distributor (if applicable – some 1990 Econolines may have a distributorless ignition system). Look for broken wires, loose connections, corrosion, or short circuits. Pay close attention to the wiring harness near the firewall, as it's often subject to wear and tear.
* Pickup Coil (Distributor): If your van has a distributor, the pickup coil inside is responsible for sensing the crankshaft's position and triggering the ignition module. A faulty pickup coil will prevent the module from sending the signal to fire the coil. This is a common culprit in older vehicles.
* Crankshaft Position Sensor (CKP Sensor): If it's a distributorless system, the crankshaft position sensor (CKP) plays the same role as the pickup coil in a distributor system. It provides the signal about the crankshaft's position to the ignition module. A faulty CKP sensor is a likely suspect.
* Power Supply: Verify that the ignition system is receiving the correct voltage. Use a multimeter to check for power at the ignition switch and at the ignition module's power input. A low voltage or intermittent power problem could prevent the system from functioning correctly.
* Ignition Control Module (ICM): Even though you've replaced the *ignition module*, on some vehicles, the actual module is part of a larger integrated control unit called an ICM. A faulty ICM can sometimes be mistaken for a module issue, but it's a separate component that's hard to diagnose. Check the wiring and power supply to it also.
* Neutral Safety Switch (NSS): On automatic transmission vans, the NSS prevents starting unless the transmission is in Park or Neutral. A faulty NSS will stop the ignition system from working.
Troubleshooting Steps:
1. Visual Inspection: Carefully inspect all the wiring related to the ignition system. Look for any obvious damage.
2. Continuity Test: Use a multimeter to check the continuity of the wires between the ignition switch, the module, and the coil.
3. Voltage Test: Check the voltage at various points in the ignition system with a multimeter. Make sure you're checking with the key in the "ON" or "START" position.
4. Test the CKP Sensor (or Pickup Coil): These sensors can be tested with a multimeter following the instructions for your vehicle's specific model. Often, they have a set resistance that can be measured. You'll need a wiring diagram to find the sensor's location and correct testing methods.
5. Check for Codes: If your Econoline has an onboard diagnostic system (OBD), check for diagnostic trouble codes (DTCs).
Important Note: A wiring diagram specific to your 1990 Ford Econoline van is essential for accurate troubleshooting. You can find these diagrams online (some are free, some are subscription-based) or at an auto parts store. Using a wiring diagram will help you pinpoint the exact location of components and wiring pathways. Without one, tracing the problem will be significantly more challenging.
