Low beams do not work fuses and bulbs are good what else should i check

What year , make and model vehicle ? Not all car makers do it the same way , you could have a relay or a electronic control module in the mix. You can go to www.bbbind.com and find a wiring diagram for your type vehicle . It would show what all is involved in you headlamps ! Just click on technical information and from there click on technical service bulletins and wiring diagrams.Then at the bottom of the next page click on user agreement,I agree Click on wiring diagrams and enter your cars info ,year ,make. an model engine size an system lighting ,then subsystem headlamps ! If you need any more help just ask. I have GM an ford factory service information if you should happen to have one of these make vehicles ! Hope this helps you !

Could be hi low switch, lights use same ground for low and hi