85 won't start

Is NA 1985 300zx. i was redoing interior carpet to different color and had to unplug vats system (underneath passenger seat) and ever other wiring underneath the passenger seat and driver seat. When I went to install battery wasn't getting any power so I thought maybe vats but now I can't find one plug in underneath the passenger seat but I feel like that can't be the culprit. I undid the interior like 3 weeks ago so I don't rememebrr where every little bolt and wire goes to. If anyone can point me in the right direction it would be greatly thanked