I just purchased a 2004 durango SLT and for some reason the heat are blowing out the dash vent and won't move when the switch is set to floor. 2nd generation durangos much different than my 2000 1st gen. I checked fuses and can't find any that are blown. I was told that the flaps that direct the heat are run by small motors but I see in a post here that it might be a vaccum leak. Could someone tell me which system a 2004 uses so I can investigate in the right direction. All advice welcomed, Thank You.