Headlight Switch Test
WARNING: This page is about a different car, the 1994 Chevrolet Lumina. However, it is still accessible from the selected car via links, so may be relevant.
Battery voltage should always be present at headlight switch terminal "F" (Dark Green wire). With headlights on, voltage should be present at terminal "G" (Yellow wire). If voltage is not present at any indicated terminals, check wiring and switch.