Suddenly the low beam headlights don't work on 2004 Chevorlet Suburban. I have checked and replaced the relay. That did not help. So is it the dimmer switch? I cannot figure out to check the dimmer switch. Anybody have any experience with this about the low beams not working. What else should I check or replace? Thanks!!

 

I would check the bulbs. It may be unlikely for both to be bad, but it could happen. You can check to see if the voltage for the low beams are getting to the bulb by unplugging the socket and checking with a meter.

 

Ok, I did that..........both bulbs when I tapped on them started working! Thanks