Ignition Key Lock Cylinder Sensor
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 1993 Mercury Cougar, 1993 Lincoln Town Car, 1993 Lincoln Mark VIII, 1993 Lincoln Continental, and 1993 Ford Thunderbird. However, it is still accessible from the selected car via links, so may be relevant.
Disconnect anti-theft control module. Using a digital volt-ohmmeter, measure resistance between pins No. 10 and 26 at wiring harness connector. Resistance should be 145-175 ohms. If resistance is not 145-175 ohms, repair circuit No. 936 (Dark Green/White wire), or replace lock cylinder sensor.