Hi,  I have a meriva and cooling fan never comes on. Over heats at Idle. I've replaced the fan resistor in fan surround still doing it. 

Any ideas? Thanks 

 

i have the opposite problem my fan never goes off.

Looking at you tube it seems there are sensors that control two relays both are normally off  so l am guessing in my case it is either a sensor malfunction or a relay malfunction,

l guess in your case that could also be a potential cause not reading a temperature so thinks all is fine