I bought shell car and had to redo all the wiring inside and out since some idiot thought they had to change the whole car wiring for the swap. So I went to the wrecking yard and got the right wiring harness for everything. So I got the swap done and turn the key on to see if the fuel primes at all which it didn't. So I checked the power on the fuel main relay it had 12 volt power then I went under the backseat to check power on the wire to the pump it got weak voltage under 4 volt? So there's two seperate power going to the pump? Where would be the problem for that not getting 12 volt power to the pump? Any help would be greatly appreciated!

 

Is the ground for the fuel pump good? Check all the wiring connections going to the pump and make sure that they are secure and clean.

 

That's a possiblitly the ground is bad... I need to get under the car and check the wiring from the under backseat to the pump. I know I got all the ground hooked up in the engine bay and under the dash. So there must be another wire I need to look around the tank?

 

The fuel pump is grounded to the tank. I would also check the wiring connection that is under the rear seat.

 

I still haven't gone under there and look at the wire.. however I tried to start today and it started? thought that was weird and checked the power again and it was still weak?