My Son's 2006 G35 coupe the Right side Headlights are not working , Checked and replaced all fuses ( Inside and under the hood and behind Battery ) Checked and Replaced all Bulbs . Do the lower marker/ Running lights work off the same Ballast as the High beam ( D2S ) or what should I check ?Should I replace the Ballast ?

Individually swap components from the side that works to the side that doesn't work until you narrow down exactly what the problem is.

Start with the lamp, that's the most common, then swap the ballasts.

Don't touch the glass part of the lamp with your fingers, the oil from your skin will create a hot spot and quickly burn out the lamp.

The Bulbs were replaced, ( And checked on the Driver's side to know they were working ) were installed with me wearing Cotton Gloves, to avoid any transfer of oils to the bulb, then all fuses were replaced. What I'm wondering is if the Ballsts control all bulbs

No. The ballasts are only to fire the xenon/HID bulbs (main/high beam on the '06-'07).

I'll suggest downloading the factory service manual from Nicoclub. Start with "Lighting System"/Section LT for your year.

Thanks for the heads up for the NicoClub lots of great manuals and trouble shooting tips

I would definitely swap ballasts between sides because it sounds like that's your issue.