have new 12 v gage. new sending unit. getting 0-40 ohms on sending unit when i move the arm. getting (minus 10-12v) on back of gage when key turned on.
tank is about 3/4 full and i can get about 25 ohm reading on sending unit.

gage goes to Empty when key turned on.
tried new wire from gage to sending unit-same response. is my problem that i am getting a minus voltage reading?? this is a 12 volt conversion with negative ground. could the sending unit be shorted out?? help

Doug B
\'51 GMC 1/2-Ton Longbox