Re: MK2 Fuel Sender
Check the instrument voltage regulator.
It is a "thermal" type regulator using a bimetallic strip contact to drop the voltage used by the fuel and temperature gauges. The output of this regulator is a pulsed voltage that averages down to around 5.6v rms.
It looks like yours may have failed and placed 12v across the gauge and sender ?
That would have the effect, on the sender, of burning it out. The gauge may have been damaged as well.
As a test...
If you connect a 22 ohm (1watt) resistor from the fuel sender wire to ground (chassis) your fuel gauge should show about 1/2 full.