My 300zx is giving me some issues. I have only had the car for about a week. I’m trying to sort out my dash issues because my digital dash isn’t working, my radio isnt working, and the hvac system is making a constant hum unless unhooked. So I’ve been checking some things out. All of my fuses are good. I’m getting power to all interior lights along with my power seats, my head lights, dash lights, with a few others. I’m thinking it’s a grounding issue. I have cleaned and replaced my grounds throught the engine bay and they all have been tested with a multimeter before and after and have good connection. But when moving to the inside the only ground I can find is one ground strap above the glove box which has terrible connection. My Haynes manual only shows wiring diagrams and not locations of the grounds. So I really am asking for help finding my interior grounds so I can connect them all well and some assistance with me issue.

Okay TheNG, you have a bunch of issues and a ground isn't probably goign to fix those. The digital dash is our best friend and your worst enemy. They have 2 major components, the dash itself and the "Digital Dash Controller" a box that is essentially the brains of the operation. One of the two is out, if the whole dash is out than the controller is probably your issue.