Hyundai Repair: low beam headlights, 2002 hyundai sonata, ground circuits

Question
QUESTION: 2002 Hyundai Sonata LX (6 cyl).  Low beam is not working.  Replaced bulbs, still only high beam.  Checked fuse by steering wheel---o.k.  I see in my user's manual there is a junction box somewhere under the hood.  Could something be wrong there?  If so, is it something I can replace like a fuse?
ANSWER: The problem won't be in the junction box.  Anything that occurs in the junction box would affect both lamps.  You may have a problem with the wiring to the lamp or the bulb may have been bad.  One way to check quickly is to place a test lamp across the teminals of the bulb connector.  If the lamp lights when the low beams are on, you've just showed that both the power and ground circuits to the bulb are okay.

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QUESTION: Both headlights are affected----I only have high beam on both headlights.

Answer
You can still do the test lamp check I mentioned in my previous answer.  

If both low beams are out, you could have a blown low beam fuse or a bad low beam relay.  Both are located in the underhood fuse box.  It's easy enough to pull the fuse and check it.  To check the relay, swap with the high beam relay and see whether the inoperative circuit moves to the high beams.  

Another possibility is that there's an open circuit in the headlamp switch.