Hi and thanks for using 2CarPros.com.
Any electrical issue can be difficult. However, you need to keep in mind, it has a starting place and ends by a ground. The first things I would do would simply begin at the fuel pump to determine if you have both a good ground as well as a power supply. From that point, you will need to work backwards to find where power is lost or to repair a ground.
I realize you've done a lot already, but I want to start simple. Here is a video on how to use a test light:
Additionally, here are directions on how to properly check wiring:
I have attached wiring schematics from Alldata which reflect your specific vehicle. They focus on the fuel system, so it shows from start to end. I hate to say it, but start at the pump and work backwards. It can be a headache, but has to be done.
I hope this information helps.
Images (Click to enlarge)
Tuesday, May 8th, 2018 AT 7:04 PM