This is commonly caused by a plugged AC condensate drain. Look for a 4" rubber hose with a 90 degree bend hanging down on the passenger side of the firewall under the hood. Squeeze the end of the hose to open it up. If nothing comes out, squeeze the wire ring holding it on and pull it off the plastic tube, then carefully poke a pencil into the tube to dislodge the debris.
Sunday, July 7th, 2013 AT 9:50 AM