87-91 F350 Fuel Gauge Ohm Reading

[AussieAndy]

Does anyone know what the ohm input is for a 1990 F350 Gas 460 fuel gauge on the dash , , It did have the dual tanks but the previous owner removed the front tank and the back tank sender is operating between 15-155 ohms The dual switch on the dash reads either 3/4 full when the rear tank is empty or pegged past F ( Dead Shortmaybe) as the front tank is not there ?
Any Ideas are greatly appreciated

 

[Fellro]

It's been a while since I worked on such when my diesel was being troublesome. It may well be the resistor in the tank is shot, unfortunately a very common issue.

 

[AussieAndy]

Thank you for the input , I do know that the ohm reading on the sender is 15 - 154 my concern is that the wrong pump and sender were installed and it should be a 0-90 ohm , Do you know what the range of Ohms is on the fuel gauge , That will dictate what the range should be for the sender
Sincerely

 

[Fellro]

'87-up reads FULL for open circuit (disconnected); EMPTY for short to ground.

Yes, the dash switch can affect the gauge without affecting pump operation, and it's common. No, the mechanical switching valve has nothing to do with the gauge. At a time when you KNOW how much is in the tank, measure resistance from the fuel level terminal to the ground terminal on the tank. It should be 160 Ohms (full) - 16 Ohms (empty)

Taken from another Ford site

 

[AussieAndy]

Thank you Fellro