May gas gauge doesn't work but all other gauges do . Do you think it is
may float in the gas tank ? The truck has dual tanks and both tanks are
full of gas. Also if I switch tanks the gauge still wil not work. Thanks
again for your help. Wrenchman

Could be the gauge mechanism, a loose connection between the gauge
movement and the flexible printed circuit board of the gauge cluster,
the gauge voltage regulator (somewhere in the cluster), the gauge
cluster to wiring harness multi-connector, the tank selector switch on
the dash, or a grounding issue with both tanks.

The only way both gauge senders could fail at once past the selector
switch is if they are in a common wiring harness, a connector comes
unplugged, and they both go open at the same time.

The gauge voltage regulator is a long shot, because that would
probably knock out the oil pressure and temp gauges also. (Unless it
has a separate voltage regulator for each gauge, possible but
unlikely.) You said the other gauges were working properly.

You may have to do this the hard way - get an ohmmeter and trace the
wires from the tank senders forward, and find the open.
--<< Bruce >>--