did it, hooked up good ground with aligator clips no diffrence. Been experimenting all day. okay with no fuel in tank reading is 77.4 ohms gauge rest below empty. with 2.5 gallons reading is 49.7 gauge sets on empty.add 5 gallons reading is 37.4 gauge reads between 1/4 and empty. Its like the readings are changing each time I try it. Has any one tried to bend arm to get an empty reading on gauge with diffrent ohm reading and see what happens?