Sorry for the confusion I found this thread

https://www.dieseltruckresource.com/...roblem-149224/

What I "had" and where I'm "going."

HAD a 01 2500 TWO WD which I'm converting to 4WD. It evidently had the dealer? update where they removed the engine lift pump and installed an in-tank pump. I removed that pump, and installed a "sensor only" tank pickup, mounted a FASS on the frame.

Then I think I screwed up. I "thought" I could reach the 2 wire plug down near the engine mounted pump, and cut that off because it fit the FASS--back on the frame. I assumed I'd connect the original wires to a relay, and run the relay output bact to the FASS

THEN (at 74) I forgot what I disconnected. Ended up finding a "mystery" 2 wire connector which goes to an obviously (dealer) added relay screwed to the firewall. This is all "factory" appearing wire. So is this wire what should be connected to the (gone) engine mounted pump connector? And if so what is the best route from here?

I have a shop manual, but I don't think I have anything covering this mystery relay. Relay is mounted high in upper driver side of firewall, if you can read it the label is part of the harness

 

DId you not get the FASS with the full harness and install kit?

 

Musta figured it out......