<VV> Fuel gauge issue

[Charlie Davies]

Need help from the Corvair brain trust.  My 64 gas gauge is not giving the proper reading.

Background: Tank and sending unit was replaced in 2012 (Clarks).  Until recently, the gauge worked as expected, with one exception, it never goes below empty while the ignition is on.  I ran out of gas once because I thought I had a little left in the tank.

Now the gauge is not giving any semblance of a proper reading.

Key off - gauge reads < empty.
Key on - tank is full, gauge reads just above empty.
Key on - tan wire on sending unit disconnected - gauge reads > full.

I drained the tank, removed the sending unit.  Measured resistance on sending unit readings go from 1.65 to 37 ohms.  With the unit out of the tank we verified that moving the float does in fact move the gauge proportionally.  I reinstalled the unit in the tank, refilled the tank, reconnected the wiring, turned on the key, gauge is just above empty.

Any thoughts?

TIA

Charlie