HELP! OBD port not working

vqcolin

Currently swapping a manual into my car with revmatch. My car as of now is made from a few part outs which include engine/trans, headlight, and main dash harnesses. Ecu is from another nismo Z and the bcm and key box is from another Z. I have diagnosed the issue of why the car will not crank because the immobilizer needs to be flash and my ecu needs to be rewritten.

Problem:
OBD port to try to even scan the codes for issues
- I tried to put a bluedriver and obd linx scanner to scan for any codes for plugs I may have forgotten. The car can go to on since the bcm and key are the same. The car does however have a delay within starting it to acc to on. Everytime I try to turn it off, it will not even turn off but goes back to acc. Then after spamming the push to start, it turns off.
- When the car is on, the radiator fans spin as if the ac is on, but everything in the car works except for cruise control, traction control button and gear position from the transmission (reverse works because my backup camera turns on)

I have talked with a few technicians, tuners, and Z specialty shops, to my knowledge none of them want to see it in person. My tuner Eugene Turkov said if the fans turn on that means the ecu is not getting power and that is the clear indicator. I have to check power and my grounds plus fuse box but I have no idea what wires to even check for that or fuses/relays.

The OBD port is receiving power since it turns on those scanners I listed earlier.

Need some expert advice on what I should do and check since this is the only issue left before a immobilizer flash and tune. After that, my car is ready to go again. I stated some issues above if anyone can help with that. My cluster is an auto but another guy that sells used Z parts says they are the same for my year 2016 Sport Tech. I plugged in my auto ecu and received the same results and that has me coming to my conclusion that its the harness or fuse box. I replaced the IPDM with my original one that came with my car and same results. OBD port goes a long way as this is the only way to diagnose my car and to be coded to start.

Any idea on what I should do?

Instagram: @vqcolin if yall could dm about the possible issue as I could respond faster.