day they work then they dont? one day the right side didnt work, then the next day it did. then a couple of days later the left side wouldnt work, then just recently niether side works.
Check the bulbs to make sure they are tight. Check the connections to the headlights. It may just be a glitch, my 2003 Trail Blazer does that sometimes. The back window wiper will randomly turn on too. Strange.