Fuel gauge ??

[Anonymous]

1964 ford custom. The fuel gauge is no longer working.
How do the old gauges work?
Is it a float system? how does it send a signal to the gauge?
Where should I start looking for an answer to this problem?
SHould I drop the tank out of it???
help!
-Geoff

 

[addo]

The tank's sender unit uses a variable resistor.

Note that none of the test procedures use positive voltage.

To eliminate spark risk, the sender is actually grounding the gauge; it's the positive that is permanently connected at the back of the dash. Try switching the ignition on, and remove the boot from the sender where the wire clips to it. Ground out the wire with aligator clips. Watch your gauge. If it swings across as you alternate between grounding and ungrounding the sender wire, it's the sender.

If no movement, then check your wiring for continuity. If that's OK, you will have to remove/test the sender. Have a spare sender gasket and a tube of blue Hylomar ready (fuelproof sealant). The "guts" of the senders often corrode a little and you may need to clean or service it.

Regards, Adam.