Bulbs blew
Check fuses and high/low beam switch.
The daytime running lights work of the high beam, check those first.
Believe it or not, you might have 2 BURNT OUT LOW BEAMS. Ive seen that a few times.
there are two diff types of bulbs. High beam and low beam bulbs. If your low beam doesn't work then you need to replace those lights because they are probably blown.
low beams
No the high beam filament is independent from the low beam filament You can run them seperately or together . it depends on how the lights are set up. For instance if you have your high beam on you may have your lows running at the same time, however if your low beam is on low beam setting, your highs are always turned of It sounds like you may need to look at your fuses or your switch.
May be a bad switch
Exactly, and this is normal.Exactly, and this is normal.
you need to replace the high/low beam switch
low beam
I think the low beam lamps have two filaments. So it's possible that those low beam filaments in the "low beam" lamps are burnt out. When the headlights are on dim, only the two outside bulbs burn. When the high beams are on then all four will burn.
A short in the low beam circuit.