are you refering to the fan inside the NAV unit? if so, good thought. however, there has been 1 tiime the screen froze up and the NAV unit was cold. But the surface of the card was very hot.

I bought this car used. the dealer suspects that some body work may have been done and water gotten in at that time. since the dealer told me they would no longer cover the NAV unit. I opened it up to check for damage. I have done electronic repairs for 20+ yrs. all looked good to me.