Welcome to NICO! Sorry to hear that your car is having trouble. I'm not all too well versed in your vehicle, but can offer an option for you.
Here at NICO, we have Factory Service Manuals available free to members. Here's the link to the FSM for your car: http://www.nicoclub.com/FSM/G35/Sedan/2008/
The index is actually at the bottom of the list. Make sure to check all your fuses and relays, and inspect the old contacts the new harness plugged into to see if they're good.
BTW, I revised your topic title to something that relates to your problem.
- USE THE CORRECT TITLE: That means, make sure your title has the topic at hand. Don't title something: "I have a question" or "Small concern" or "Help!". Instead title it: "Tire tpms question" or "Rear bumper paint issue". The idea is to attract the attention of those most likely to be able to assist you.