Heat front

The gentleman I answered for, had the same problem with his 2000 Explorer. Here is the answer I provided: sixfootsix_car_guy answered about an hour ago There is a switch that redirects the air through the dash, up to the windshield, down to the floor, and out of the vents. This is called bi-level air flow. The rear seats in the explorer have their own blower motor for the heating and a/c. Most likely the primary blower motor is out. Have you noticed weak air flow when it was working? Does it blow out of the Defrost Vents at the top of the dash? How about down onto the floor boards? If that is the case and it doesn't blow just out of the direct vents, its a switch assembly that has gone bad.