1997 e 350 diesel van can't get heat out of heater. Heater core is warm, 2 doors under dash open & close when controls are adjusted from AC to heat. Blower motor works but no warm air comes out on driver side or passenger side. Could this be a vacuum leak problem? When van is off heater controls function for a while but quickly run out of vacuum. Any suggestions?
Tuesday, January 15th, 2013 AT 9:22 PM