I'm going to guess you're talking about the interior fan. Either the motor on the fan is going out, or there is some debris stuck in there. You can check the debris part fairly easily yourself. Empty the glove box, pop the retention rod on the right hand side off, squeeze the sides of the glove box, which can be difficult but don't worry about using too much force, you can't deform it, and it should come out pivoting slightly on the lower hinges. cabin filter is right there with four little tabs, give them both a pinch and that sucker slides right out. You'll be looking directly at the fan cage once its out so you can see if any thing is stuck in there.