Dumb question: Is there a sensor installed in the grille?

Cant answer your question, but can you do a writeup on the evic install? This is something I'd like to do to my 05.

Obviously you did not obtain a good model of EVIC. For KJ 2005/2006 EVIC must be from the 2005/2006 donor. I am also originally bought the old model of EVIC for my 2006 KJ and the temp gauge did not work. In the second attempt I got EVIC from 2006 KJ and everything working like a charm now.

sounds like short or bad sensor is this the sensor out of the totaled crd ? damaged the sensor

I hate to say it but being new does not rule out bad given that it worked for several days. There should be some way to test the sensor signal and connection, but that's beyond me. I also wonder how the sensor signal is processed to turn it into a digital reading. If done in EVIC circuits that might imply and EVIC problem but testing that is beyond me also.

Anyone close by that with a working sensor that could be used to test at least sensor function?

The BCM reads the temperature sensor and broadcasts that on the PCI bus.

So how do I get it to work?

Try a battery disconnect reset maybe?

Done that.

Quick way to check the sensor. Did you check the resistance of the outdoor air sensor, at 68 degrees it should read 10000-13000 ohms. And it should change value when temp changes. That will rule out that.

Quick way to check the sensor. Did you check the resistance of the outdoor air sensor, at 68 degrees it should read 10000-13000 ohms. And it should change value when temp changes. That will rule out that.