Spark Check

Perform self diagnostic QUICK TEST to check for ignition-related fault codes, and repair as necessary. See QUICK TEST in the appropriate TESTS W/CODES article in the ENGINE PERFORMANCE section.
- TESTS W/CODES - EEC-V - Continental
- TESTS W/CODES - EEC-V (4.6L) - All Others
  If no fault codes are retrieved, check ignition system wiring harness connectors for corrosion and tight fit. See the appropriate WIRING DIAGRAMS article in the ENGINE PERFORMANCE section. Clean or repair connectors as necessary.
- WIRING DIAGRAMS - Continental
- WIRING DIAGRAMS - 4.6L - Cougar & Thunderbird
- WIRING DIAGRAMS - Town Car
- WIRING DIAGRAMS - 4.6L - Crown Victoria & Grand Marquis
If wiring and connectors are okay, use Neon Bulb Spark Tester (D89P-6666-A) to check for spark at each spark plug wire while cranking engine. If spark is strong and consistent at each spark plug (one spark per crankshaft revolution), ignition system is okay. If spark is not present, go to IGNITION SYSTEMS in the SYSTEM & COMPONENT TESTING -- EEC-V article in the ENGINE PERFORMANCE section.