But let's do an obvious test. Can you swap the leads to the two
tanks; so the left shows on the right gauge and vice versa? [Assuming
such can be done legally and safely, of course -- can you placard
it or such?]

That will reduce it to gauge vs sender resistor+wiring+grounds.


On the Cherokee 140 you can swap the gauge/sender with a simple swap of
2 wires on a barrier strip under the rear seats. Check the Service
manual to see if there is a similar setup in the Warrior. The barrier
strip is probably behind the baggage area or under it.

Good Luck,
Mike