We have a 2002 Ford 150. Since we got our 4x4 fixed at the repair shop, we do not have AC coming through the vents. The AC comes out of the defrost and lower vents. If we put the digital climate control on vent then we have air coming through the vent. We changed out the climate control with a different one and noticed one of the vacuum lines missing. Is this suppose to be this way? How can we find a diagram to see why the AC is not coming through the vents?

SOURCE: 2002 Ford Expedition Climate Control System

you have a loss of vacuum. There is a small diameter black plastic tube from the engine compartment that feeds the climate controls. Check at back of control head, or there is a plastic connector under dash were other color tubes join to operate the other actuators of the system the black tube must have vacuum when engine is running. check under hood the black tube is spliced. separate the tube and check for vacuum The tube enters the firewall near the heater hoses.

SOURCE: climate control system only blow air out defrost vent

there is a good chance that you blend air door is stuck closed over your heater core and therefore not allowing the heat to flow, also your door that opens and close your direction of flow from the floor ,das,vent and defrost.your going to have to remove the lower cowling of the dash on the passenger side analso some of the center dash to actually check to see if the cable,servo motors. are acuating the doors.the issue could be just a stuck door or a misaligned cable or that it came off. that falls under the mechanical side of probabilities. electrical would most likely be a faulty selector switch or a servo motor

SOURCE: heating / air conditioning control stuck to front defrost vents

There is a vacuum leak under the hood. Find the vacuum line on the passenger side where it comes through the firewall and follow it to the engine. You system needs vacuum to operate and without it the default setting is on defrost for safety reasons.

Bill

• 424 Answers
• Posted on Oct 05, 2009

SOURCE: climate control is on defrost only the auto

Check your vacuum pump located on the right side fenderwell. see if its running. Check the vacuum hose at the hubs for leaks or damage. repair if damaged. check for other vacuum leaks such as the grey hose going to the heater control valve.

SOURCE: 2003 Trailblazer No air from front face vents

first check to see if you have power going to the actuators when you switch the switch to it location if no power replace controller if you have power and no movement from actuators replace actuator. if actuators move remove hvac box and check for broken blend doors.