I have a 2000 Grand Cherokee (Quadra drive, V8, 4X4). It comes equipped with the personal climate control adjustments for each side of the car (passenger/driver).

This past summer, I experienced a problem where the driver's side AC worked fine; however, and on occasion, the passenger side would blow heat and do so regardless of where the temp adjustment was set for that side. This problem was also intermittent vs. continuous. Now that winter has arrived, I've noticed that I now have no heat whatsoever, and it seems to be blowing vent air.

I suspect that there might be a split vacuum hose or ruptured diaphragm (if it even has one), in that I can hear a vacuum leak somewhere under the dash during acceleration. This has occurred since the summer issue began. Nevertheless, it almost seems as if there might possibly be more than one problem here.

I began taking out the glove box and surrounding shrouds this evening, as to see what I can see; however, and having had a look behind them, where the entire area is filled and obscured by the massive ventilation system, I thought it wise to consult those in the know before taking another step. For there is most certainly no easy access without damn near tearing out the entire dash.

Thanks in advance for everyone's help. Really need to get this fixed before the temp really drops.