Door Disarm Switch
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.
Using a digital volt-ohmmeter, measure resistance of door disarm switch with key removed from door lock. Resistance should be more than 25,000 ohms. Measure resistance with key in lock and fully rotated to unlock position. Resistance should be less than 200 ohms. If either specification is not met, replace door disarm switch.