If you look closely to your bulb. Their is two wires in side. Only one comes on when switch is turned to low beams. Then switched to high beams both wires light up.
Low beams - 9006 bulbs or HB4 bulbs High beams - 9005 bulbs or HB3 bulbs
Sounds like it needs a headlight switch.
It could be that the headlamps are burned out or it could also be that the high beam switch has failed.
I would start with the easy answer. Check both of your headlamps to be sure that the low beam filament is still intact. If all is well there, I would start leaning towards the multi-function switch (which is the headlamp / turn signal lever.
Low beams are burned out.
Yes. They provide a wider, brighter viewing area. I have them as high beams and low beams and I noticed the difference immediatly!
if your dims work, but brights don't then it's probably your high beam switch.
The low beam lights should be set up as the outermost headlamps. All 4 will be on the when the "high beams" are switched on
Your speed at night needs to be adjusted so that you can stop within the distance that your headlamps illuminate the road ahead.
Since you didn't include year in your question, I'll have to answer in general. It will vary depending on if you have HID or Halogen low-beam headlights (high beams are halogen on both versions). In general, the first place to look is your owner's manual - most will have instructions and illustrations. See sources and related links below for more information on bulbs.
It is a wiring problem. My mechanic followed the wiring and found where it had frayed. He spliced the wire, removed the headlight and soldered it back on. Works like new now!
change your bulbs and see if that's it.