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1995 f250 xl.
I need help diagnosing my fuel issue. My truck has the 300 inline 6 engine. What happens is when I switch it to rear tank, the engine dies, clearly not getting fuel, and the fuel gauge does not work when either tank is selected. Any suggestions?
Each tank has its own fuel level sending unit. Did they both stop working at the same time was one still working until now? Do you hear the fuel pump in the rear tank run for a couple seconds when you turn the key from OFF to RUN?
How many miles are in the truck? It's very common for the sending units pcb resistor board to wear out after 200k miles. You can test the gauge by removing the connector from the fuel tank and short out the sending unit wires with a 50 ohm resistor.
Truck has 214k miles so sounds likely. What exactly are we needing to do to test this? It sounds like I need to access the sending unit from inside the tank and use a multi meter to test resistance?
Of you want to check the sending unit, easiest way is throu the fuel selector switch. Disconnect the switch from the wiring harness. Then you need to use a multi meter to check the resistance of the brown/yellow wire to ground on the front tank, and the yellow/light blue wire to ground for the rear tank.
To test the gauge, turn the ignition switch to 'run' and short the yellow/white wire to ground. The fuel gauge should drop to 0.
Of you want to check the sending unit, easiest way is throu the fuel selector switch. Disconnect the switch from the wiring harness. Then you need to use a multi meter to check the resistance of the brown/yellow wire to ground on the front tank, and the yellow/light blue wire to ground for the rear tank.
To test the gauge, turn the ignition switch to 'run' and short the yellow/white wire to ground. The fuel gauge should drop to 0.
How much resistance am I looking for? How do I tell by that if it works? I have a feeling that’s a dumb question but I am honestly really bad at the electrical side of diy automotive.
So I do not have a brown/yellow wire for the front tank, there is however a brown/white wire that I used instead. So keep in mind that I filled up both tanks. So they should be full. On the front tank I got 44 and on the rear I got 2. When I did the yellow/white wire to ground and put the truck on run, the fuel gauge, starting at e slowly went rising up past f and when I turned the truck off it stayed in place. What is going on?
So your fuel gauge is working backwards. When you disconnect yellow/white wires, the gauge should go to "max-full". When you ground the yellow/white wire, it should go to "empty".
You should check your G100 ground. Its near the back side of your left hand headlight.
