Low Beam Headlights Problem

Low beams are not working, neither one of them. The high beams work. This just appeared to happen overnight. Do I just need to replace both low beam bulbs or could it be a bigger problem since both the right and left side quit working at the same time.

Year make and model?
Pull the bulb and with a old 12 volt bulb type test light or volt/ohm meter see if it is getting good voltage on low beam side.
Some are fused depending on year.
Also it is normal for the left and right side to go within a hr of each other.
Just like they have a built in timer.
MT

02 chevy blazer 4wd

i was also told it could be a relay as well? if it is a relay, i have a 1996 GMC Jimmy 4wd sitting in my driveway and i was wondering if the relays for the blazer and the jimmy are the same and can be swapped out?

Read post 2.
You need to check things out before throwing parts at it.
Check for voltage aT BULB.
mt

02 Has two head light setups with ZR2 or without ZR2.
Looking at the wiring diagrams it looks like the headlights are turned on with a ground setup.
Check fuses and for power to bulbs.

Power feed low beam should be yellow and black wire for left and dark blue for right low beam.
The yellow for right and left low beam should be a ground circuit wire from multi function switch to low beam bulbs to turn on bulb.
MT