I bought a new VDO oil temp gauge and sending unit. I'm getting 13V power at the gauge. Light works on all three console gauges. Voltage and oil pressure gauges work fine. The sending wire Green/Black gets 7.3V on acc key turn and 8.3V car running. Any clues?

Edit: The old gauge never worked since I owned the car.

Disconnect the wire attaching to the temp sensor. Then measure the resistance from battery cable ground to the sensor terminal.

Go ahead and reconnect that wire back onto the sensor. Now turn your attention to that sensor wire behind the gauge cluster. Disconnect it from the gauge and measure the resistance on that wire to ground. What is the resistance of these two measurements? Do they match?

Should there be continuity from the sending wire at the temp sensor to the sending wire at the gauge? (Green/Black)

post pix of parts or part numbers