1991 geo tracker doesn't usually start in colder weather.

[fixkick]

AS the nice drawing on my pump page clearly shows, the wiring harness DRAWING
shows you the 2 wires (Plus/minus and PINK/black) go to a connector at the center rear of the rear bumper, and is 100% visually inspectable and the voltmeter works that too.
this is the wire part on the way to the thank

here is top of tank views, a real 2door.