In-tank fuel pump grounding question

[jovial_cynic]

I was doing some wiring cleanup on the SR20DET install and something weird happened. I pulled the ground wire from the fuel pump (which is in the tank), and figured that the pump would not kick on when I turned on the ignition. However... With only the power line from the fuel pump relay, the pump powered up like normal.

I checked for continuity between the ground terminal and the tank, and it looks like the fuel pump is currently grounded internally. I don't even need the ground wire.

Now, I know the tank is grounded to the body through the bolts - that's the only way the single-wire fuel level sender could work. But I didn't think the pump would also be connected electrically to the tank (and thus, grounded to the body). If that's how it is supposed to be, great. I'll just have some redundant grounds. But if that's not how it is supposed to be, do I have some faulty connection that could potentially cause an in-tank short?

In the meanwhile, I'm completely bypassing the in-tank pump and using and external pump until I know that the in-tank pump is safe!


(obligatory picture: prior to getting it back in the car)

[okayfine]

Any idea what the in-tank pump came from? You could then look up a fuel wiring diagram for that car and see how it is supposed to be wired.

[icehouse]

The rule I try and follow. If Nissan could have ran one less wire or relay they would have to save money. I'm sure it has something to do with safety being in the fuel tank and all.

[jovial_cynic]

I believe I yanked the in-tank assembly from an old Honda Civic. And I had to fabricate a few bits to make it work properly in the 510 tank... which makes me think that I'm on my own for figuring out the wiring on it.

I'm actually planning to run through all the electrical to make sure all the ohms and voltages are where they're supposed to be. I feel like I'm chasing down some gremlins, and with so many variables to deal with, it'd probably best that I make sure everything is in range.