2001xcv70 temp gauge was going up and down

[z28chuck400hp]

was driving 2001 v70 xc turbo and temp gauge kept diving to cold like it was unpluged.today reads cold and does not move.Removed therostat and heated it up in water to about 190 deg. and it opened.put it back together without thermostat and disconnected fan.Tryed disconnecting the electronic cooling sensor on the thermostat housing and jumped the terminals and the gauge still did not move...shouldent the gauge come up when jumped?Is it possible that the water pump has poor flow...afraid to let wife drive the car...car has heat to the dash..?????