what do you mean when you say you checked the fuses and the relay? Are they working correctly?
are the Left low beam and right low beam fuses #7 and #9 in the underhood fuse block are good and power up when the headlight is in the on position? Does the relay click and turn on the power to the two fuses? turn off the headlights and the power to the fuses goes away?
if the fuses are powering up when the headlight switch is on low beams ( the yellow wire to the left headlight and the white and tan that changes to a yellow wire at the right headlight) Then verify that power is getting all the way to the headlight bulbs. Verify that you have a good ground for the black wire at the headlight bulb too. But if your high beams are working good then the ground should be good.
if the relay clicks but the power doesn't power up the low beam fuses try a different relay and see if it works then. If it still doesn't power up the low beam fuses make sure you have battery power at the relay leg that is power all the time. (pin #30)
if the relay doesn't click you should have you BCM scanned and see if it getting the signal to turn the headlights on. Or that the pink and white wire from the multifunction switch is grounding the low beam relay (pin #86 on the relay)