Test 11, Check PWR GND To EDIS Module
WARNING: This page does not describe the selected car, but rather 11 other vehicles, including the 1991 Ford Ranger, 1991 Ford RV Cutaway, 1991 Ford Pickup, 1991 Ford F-Super Duty, and 1991 Ford Explorer. However, it is still accessible from the selected car via links, so may be relevant.
With key off, set DVOM to 2-k/ohm scale. Measure resistance between breakout box pins No. J27 (PWR GND) and J7 (BAT -). If resistance is less than 5 ohms, replace EDIS module. Remove all test equipment, and check for fault codes. If resistance is greater than 5 ohms, repair open circuit, reconnect all components and check for fault codes. If vehicle still does not start, go to next test.