Headlight issues
 

1992 Chevy g20, 5.7ltr. 106,000 mi... Van’s been sitting awhile. Fired it up & was going over the lights. Signals weren’t flashing, changed out the flasher & bulbs. Fixed. Headlights- right side works fine, dimmer works. Left side, nothing. Changed out the headlight switch. Still nothing. Light pin sockets showing low to no voltage. Can’t see how there could be a short, followed the wires to the firewall... bad dimmer switch? It clicks. What could it possibly be? Little help please?

its probably a bad ground...your head light has 3 wires to it. one is a ground. jump the ground on the headlight bulb to chassis ground and see if it then shines bright. then you know you have a bad ground in the harness.