White Wire Circuit
- If spark occurred at step 3) of BASIC SYSTEM TEST, connect voltmeter positive lead to ignition coil's "BAT" terminal and negative lead to ground.
- Check voltage while cranking engine. Voltage should be within 1 volt of battery voltage. If not, repair White wire circuit feeding positive terminal of coil.
- If voltage is okay, crank engine and check for sparks at modified plug. If sparks occur, ignition system is okay. If none occurs, puncture White wire with a straight pin between control module and 2-wire connector. See Fig 1.
- Connect positive lead of voltmeter to straight pin and negative lead to ground. Crank engine. Voltage should be within 1 volt of battery voltage. If not, repair White wire circuit and repeat White wire circuit check.
Courtesy of FORD MOTOR CO.
- If voltage is okay, substitute a known good control module (but do not install). Repeat test procedure from step 1). If sparks now occur, reconnect original module. If no spark occurs, replace defective module with a new one.