1996 Chevy Silverado headlights

Welcome to the forum. There is probably a multiwire connector under the dash, close to steering column, that is for circuits going to and from the steering column. Check purple wire for voltage. The high beam circuit is straight off the dimmer switch. The low beam circuit goes through the dimmer to the drl relay, When the relay isn't energized, there is continuity on the low beam circuit to headlamp. The purple wire I mentioned carries voltage for low beam to drl relay. If that wire isn't hot, suspect dimmer switch. If the circuit is hot and no low beam, we''ll have to check drl relay and wiring circuit. The info I looked at was for sealed beam, not quad. All repair info says when doing testing around steering column to disarm air-bag for safety.