Low beam headlights won't come on. on 2005 Chevrolet Trailblazer

Low beams won't come on. Fuses good bulbs good. Replaced headlight switch and still no low beams. Also gas gauge has been intermitent for months. You fill the tank it goes to full and as soon as it gets there it goes right to empty. Please help.

Asked by for the 2005 Chevrolet Trailblazer
possible short best to have a pro diagnose/repair