ALT Fuel Switch
WARNING: This page is about a different car, the 2002 Ford Pickup and 2002 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
For ALT fuel switch or circuit testing, repair by symptom. See SYMPTOM DIAGNOSIS under SYMPTOMS in TROUBLE SHOOTING - NO CODES - EEC-V - BI-FUEL article.