check your vacume feed hose it probably got disconnected. goes from about the center of the firewall down to a vacume port on your intake/carb it possably is hooked to a T or two.84s104x4 said:I need help with my heater. I have no air flow coming out of the vents or the defroster. The fan is good. The motor is good. And i cant find any leaks where the air would be venting out. Would the heater core be the problem. I am stumped.