Problem Audi a3 cooling problems


Good evening!

I have a big problem.. I've been searching all day but I haven't found anything to help me. My story starts like this:

For a few days when I started the car (A3 2003 1.6 BFQ) it shows me an error on the board with the coolant. I vaguely put the com and he gave me the temperature sensor. I went to the store, bought it, installed it, but as the water rose above 60 degrees, it gave me the error. Conclusion my thermostat was stuck open.

I ordered another BEHR thermostat (the partially electric one, which means it also has a plug on it, it is more expensive) because the original one removed from the car was also BEHR which should open at 105 degrees...

Everything is fine and dandy... I also installed the thermostat... and this is where my problem starts: my thermocouple doesn't turn on anymore, that is, I put the ignition switch on the car, I walked with it turned on in small increments until the temperature reached almost 108 degrees (so the com vaguely indicates, on the board it seemed less) but the thermocouple did not start

What I also noticed is the fact that the hose that comes into the thermostat is "hot", that is, not as hot as the others.

Please tell me where the problem could come from, what else I should check or what needs to be done... I'm desperate

I can't close/open the thermostat from vag-com to see if it works correctly?

Do you have any idea how I can check the new thermostat if it is functional?

I saw that it also has a plug (so it also has an electrical part) and I suspect that it should not be boiled to see if it works....

I am waiting for you with an advice/opinion.