Hello, 1995 Caprice with Twilight Sentinel...I always have the T/S switched off. Headlights low and high do not work all of a sudden. Everything else works. Put in new lamps and the under dash column dimmer switch...Nothing..Does the actual physical headlamp knob switch quit on these? I have not probed anything yet with a tester....Any ideas? Does a bad Sentinel switch kill the headlights even though it is switched off?...Hot as Hades here in Florida so this is a real drag working under the dash now....Thank you much, Uvaldi..