Did you ever solve this issue? I’m experiencing the same issue as well.

 

U are also only getting 2 volts at the wires?

 

In the bottom picture the BLUE wire from the PAC side isn’t connected to anything. According to Wrathernaut’s wiring chart that wire should be connected to the RED from the head unit harness. So you’ll have a RED & BLUE from the PAC connected to the head unit RED.

 

I encountered the same issue recently on a 2006 Minnesota (road salt) g35x. After tearing the dash apart and tracing the voltage drop as far back as I could, reseating the fuse near the battery under the hood fixed it for me. Noticed corrosion on the fuse terminals. Interestingly, the ignition switched +12v was fine, so it must go through a different non-corroded fuse.

 

what fuse did you reseat

 

This was 5 years ago. I don't have the car any more. Try all of them.