front drivers lights do not work on my 2010 vw beetle,connections,fuses,bulbs ok

i did use a test light and there was power at the female socket, i am not sure thow , there was power at the single prong on the bottom and power to the next prongs just above but no power at the top prongs i am not sure what those top ones are for and they may not have power until something is turned on. I turned on the head lights fog lights running light but the drivers side did not work, now if it is a ground problem on that side where would i find the ground for those lights?