Test 16, Check VRS Amplitude At 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 and ECA connected to breakout box, disconnect diagnostic cable negative lead from battery negative terminal. Set DVOM to 20-volt AC scale. Crank engine, and measure voltage between breakout box pins No. J35 (VRS+ E) and J48 (VRS E). If settled voltage is greater than 0.4 volt, go to TEST 46. If settled voltage is less than 0.4 volt, go to TEST 25.