Temp Gauge erratic & jumping

I have a problem with a erratic temperature gauge that jumps from 0 - 130 C and everywhere in between. I assumed the problem was with the green sending unit and replaced it three times. Once with a used OEM, a brand new after market, and another OEM sender. unfortunately replacing the sending unit hasn't fixed the problem.

I hooked up VCDS and notice that the ENGINE measuring block #1 shows and maintains the correct temperature regardless of the instrument cluster gauge movement However INSTRUMENT measuring block #3 shows erratic and sudden temperature changes.

I performed a instrument cluster output test using VCDS and the temperature gauge appeared to do a normal sweep. The instrument fault code is G2 sensor SHORT TO GROUND.

Is the problem in the wiring to the instrument cluster or with the cluster itself?

wiring, and likely not on the dash side either unless work was done under the dash like heater flap or heater core. so start at the sensor and track it back toward the cable tray that runs from the battery toward the windshield.