My fuel gauge reads different each time I cycle the ignition on. Example: I had 450 miles on the tank of fuel and I cycled the ignition 3 times, once it read 1/4 then 3/4 and then back to 1/2. With the miles on that tank of fuel, the 1/4 reading should have been the most accurate.

I've cleaned the connecter at the sending unit. After searching every thread I could find, I'm thinking maybe the ground. The sending unit has 2 wires coming off it going to the connector. One going to the controller and one being a ground (according to the haynes prints).

Does anyone know where the ground wire actually connects to ground? Once it leaves the connecter at the sender, it goes into the wire protector on the frame. I'd rather find the ground point and redo that connector. Plan "B" is to splice into the ground wire at the sender connector and run a second ground wire to the frame.

What do you guys think? I'm really hoping someone knows where ford put the grounding point. For all I know, it could be behind the gauge cluster. Thanks for any help, Mark

 

Npt 100% sure but I think it is next to the air cleaner on the side of the engine compartment I goes through connector 101 and then through Splice 102 right near that area. You can test the gauge with a 15 and 160 ohm resistor.

Gauge Test — Fuel

Preliminary Setup

Disconnect the fuel level sensor and pump C441 (except Motorhome, except California), C442 (except Motorhome, California only), or C300 (Motorhome only). Connect one lead of Instrument Gauge System Tester to fuel level sensor and pump, circuit 29 (YE/WH), and the other lead to ground.
Check E (Empty) Indication

Set Instrument Gauge System Tester to 15 ohms and turn the key ON. Wait one minute. The fuel gauge should indicate E (empty) or below. Turn the key OFF.
Check F (Full) Indication

Set Instrument Gauge System Tester to 160 ohms and turn the key ON. Wait one minute. The fuel gauge should indicate F (full) or above. Turn the key OFF. Return to the pinpoint test.

 

Thanks, Mark