hey guys, i’m new to the forum so hope i am posting this correctly. i put a new motor in my g35 coupe and don’t remember the correct location for all of the grounds. if anyone knows the answer to this or has i diagram i would appreciate it a lot. thank you.

 

Wow, that's big work you've done there. And without the Factory Service Manuals I don't know how you managed it. But luckily they are available here:
https://www.nicoclub.com/infiniti-service-manuals
Scroll down, click G35/G37/Q40, scroll down, click G35, click Coupe, click 2003, and that is your entire set of manuals. Maybe start with "Power Supply, Ground and Circuit Elements". Clicking on that brings you to a "viewing page" but below the "viewing window" I suggest you "click here to download a copy". That manual is not an easy read but all the info you seek should be in there. Good luck!