Faulty Fuel gauge

Check all the wiring first
My main tank gauge didnt work for over a year and ot was only a broken wire

Mark,
Just to rule one thing out. If the fuse is blown other lights or gauges on the dash won't work.

If you break the wire to the fuel tank the gauge should move to over full with the ignition on. So that will prove the gauge is ok.

Their is a plug on the back of the gauge which is pretty easy to access so you could have a look at that.

Other things are, the wire to the fuel tank sender is shorted to earth which will show an empty tank or the sender itself is stuck down or the float has fallen off. The sender rheostat could also be faulty itself could. If the earth is broken off the tank sender the gauge should be reading over full.

If it is the sender it is not to hard to drop the back tank.

Hope this is of some help

Mark,

We had the same problem on a 75 series, on rear tank, and one of the internal baffles had broken away and kept the float at empty.

Pulled the sender out and that rectified the problem until the tank was near empty again, and same problem reoccurred.

Bob