White Wire Circuit
- If sparks occurred in step 3) of Basic System Check, connect voltmeter positive lead to ignition coil's positive ("BAT") terminal and negative lead to ground. Check voltage while cranking engine. Voltage should be within 1.0 volt of battery voltage. If not, repair wire feeding positive terminal of coil.
Courtesy of FORD MOTOR CO.
- If voltage is OK, crank engine and check for sparks at modified plug. If sparks occur, ignition system is OK. If none occurs, puncture white wire with a straight pin between control module and 2-wire connector. See Fig. 5.
Connect positive lead of voltmeter to straight pin and negative lead to ground. Crank engine. Voltage should be within 1.0 volt of battery voltage.
- If not within 1.0 volt, repair wire feeding module white wire and repeat white wire circuit check at step 1).
- If voltage is OK, substitute a known good control module (but do not install). Repeat testing from step 1). If sparks now occur, reconnect original module. Retest and if no spark occurs, replace original module with a new one.