When chasing a problem like this, I always use an old sealed beam halogen headlight to make sure you have good power all the way to the pump. That way you’re putting a load on the circuit. Voltage meters wont tell you if the circuit can carry a load. Of course you could go from the front to the back. I think you can go to the Zones website to look at diagrams and locations of components. Don’t forget to check your fuel pressure to make sure you’re still chasing the right animal.