Fuel gauge issues

[TerryM]

Hi everyone, getting to the end of the restoration on my 65 fury and sorting through some electrical issues. Fuel gauge didn’t work at first but a couple of days ago it started working but shows over full. This morning I jumped in to move car and for the first time it actually read correct at a quater full( it’s only got about 25litres in it).But when I put the car away tonight it’s gone back to reading over full. Anyone have any ideas on this. Regards Terry

 

[FURYGT]

I would check and clean the bulkhead connectors and would also check the ground strap that goes from the fuel tank sending unit to the steel fuel line as corrosion or a broken ground strap can give you erratic readings.

 

[3175375]

View attachment 424763 Hi everyone, getting to the end of the restoration on my 65 fury and sorting through some electrical issues. Fuel gauge didn’t work at first but a couple of days ago it started working but shows over full. This morning I jumped in to move car and for the first time it actually read correct at a quater full( it’s only got about 25litres in it).But when I put the car away tonight it’s gone back to reading over full. Anyone have any ideas on this. Regards Terry

Someone recently went through trouble with the fuel gauge and sending unit and reported on this forum.
IIRC, they had issues with the ground from the sending unit to the tank / chassis.

search for that or if you are on the nice list, someone will remember the thread and post the link here.

 

[CBODY67]

The fuel gauge works off of a ground system, with the variable resistor in the sending unit modulating things. If you checked the operation of the sending unit earlier in the restoration process, then check the electrical connections in that circuit . . . ALL of them, as noted.

Happy Holidays!
CBODY67

 

[traintech55]

I would check and clean the bulkhead connectors and would also check the ground strap that goes from the fuel tank sending unit to the steel fuel line as corrosion or a broken ground strap can give you erratic readings.

The wiring for the fuel sender DOES NOT run thru the bulkhead connector. It runs down the drivers side under the carpet to the trunk.

 

[HWYCRZR]

The full reading of your gage should be around 10 Ohms, 1/2 tank around 23 Ohms and empty around 74 Ohms. The full reading likely means you have a short to ground in either your sending unit or your wire between the sending unit and gauge.
Train Tech is correct the wire runs from the rear hump under the rear seat down the LH side channel and up by your vent where there is a connector then to your IP. Here is a thread that may have some useful information related to the fuel gauge calibration. There may be some tidbits that you can pull to trouble shoot your case. Also other links to sending units rebuild in there as well.
Fuel Sender calibration using Meter Match