F250 Fuel gauge
I have a 1997 Ford F250 Heavy Duty with a 7.3L, it has dual gas tanks. When i flip the switch to tank one, the gauge drops to empty. There is diesel in the tank and it continues to run fine. Any ideas on what is causing the gauge to drop to empty?
the sending unit is bad in one tank. either that or wires to it.
It could also be an open connection at the switch. The sending unit provides the ground for the gauge. The better the ground, the fuller the gauge. A empty gauge indication would be no needle movement due to no ground.
Agree it sounds like the sender, it is possible that the float has came off the sender and sits on the bottom so you get an empty reading. I believe that this year of Ford if you have an open circuit in the fuel gauge system the gauge goes past the full mark.
your right tennisshoes. Its susposed to read 145ohms when full and 22.5ohms when empty. An open condition would make it read over full. the signal is shorted to ground somewhere. you could unplug the sender on the affected tank and if it reads full then you know its the sender. if it doesnt change you have a wire shorted to ground.
the switching valve under the truck also switches the gauge circuit. lots of salt and water down there check for corrosion in the elec. connections. it may require a new valve
I just replaced my rear tank and fuel pump on my 89 F250 with 351W. when the tank is full it reads normal till 3/8 of tank left and the gauge will start to rise back up to full.
Christopher On my 1997 7.3 rear tank was reading empty when it was full. Ford wanted $500.00 for new fuel sensor. I took my tank down and removed the sending unit and found my float was full of fuel and had a crack in it. I found a new float on Amazon made of brass like the original and the cost was like $12.00 it just snapped in to the arm
The wire harness only has 2 wires going to the tank and the tank harness has 4 wires coming out
GuruH413R late model fuel tanks have 4 wire connectors, power and ground for the fuel pump and the fuel gauge signals in and out wires. in other words wrong tank for your rig.