With my Audi 80 it is still too hot without the fan starting. I have already installed a new thermoswitch and also a new fan. Only the fan starts when the car comes to just under 100 degrees. At 90-95 degrees the fan has to start at that first stage. I read this with the ventilation by reason of the open water cover warm running and heating on full puller to fan starts and the hoses press if there are air bubbles in it. However, when the lid is open the lower thickness tube did not get warm even with over 90 degrees not only the upper thick tube became hot. What else can it be that the fan starts so late. Can not make such an ASU and doesn’t know any more. Can you test or notice somehow whether the thermostat in A…. is. I am no expert at screwing and needed some tips.