Check Mode Selector Switch
WARNING: This page is about a different car, the 1995 Ford Probe. However, it is still accessible from the selected car via links, so may be relevant.
Disconnect mode selector switch connector, located behind control panel. Measure resistance between mode selector switch Blue/Yellow wire and Black wire terminals. If resistance is greater than 10,000 ohms, repair short to ground in Blue/Yellow wire. If resistance is less than 10,000 ohms, replace mode selector switch.