Analog Volt-Ohmmeter (VOM)
WARNING: This page is about a different car, the 1995 Ford Pickup, 1995 Ford Econoline, 1995 Ford Club Wagon, and 1995 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
1) Turn ignition off. Set VOM at 0-15V DC range. Connect positive lead of VOM to positive battery terminal.
2) Connect negative VOM lead to Self-Test Output (STO) terminal of Data Link Connector (DLC). See Fig 1. Go to KOEO SELF-TEST. Activate KOEO SELF-TEST by connecting jumper wire from Self-Test Input (STI) pigtail to signal return (SIG RTN) terminal at DLC with ignition on.