Hello to all.I have XC60 2015 D4, a few weeks ago my cabin ventilator stop working. My auto mehanic changed rheostat and ventilator start working again but immediately I got a new problem that ventilator works unevenly, a few seconds really hard than slow and hard etc. Sometimes also stop working. After I turn off and on, ventilator work again. What can be a problem there? Is that can be because of rheostat something or else? There is no any error in system.Sorry guys if my English is bad.