ford f150 ac vent problem
 

2003 ford f150 only blows out vent only. when switch controls to floor or defrost it still comes out vent. any suggestions. thanks

sounds like a mode door actuator is stuck

where is the mode door actuator

On most vehicles its in/under the dash, close to the center. its the actuator that controls the flow of air to the vents/defrost/floor vents.

Start with the easiest first. Check fuse #2.24 10amp in the fuse box inside the vehicle. This provides power to the function selector switch (Off, Max, Normal, Vent, etc.). If fuse is good there are several other possibilities. I would remove the floor duct on the passenger side where the panel/floor door vacuum control motor is located. Ther are two vacuum lines going to it. Turn the selector switch from panel to floor with engine running and see if the motor pulls a vacuum on the two ports (with vacuum lines unplugged from motor). The vacuum should switch back and forth as you adjust the selector switch. If there is no vacuum on either one probe into the wires going to the vacuum motor with a voltmeter and see if it is getting voltage when the selector switch is moved back and forth. If it is getting voltage, the motor is bad. If it is not getting voltage you may have a wire or selector switch issue. Good Luck.

the selector for defrost, vents or floor (the knob) is vacuum controlled. two vacuum cylinders pull doors to direct the air up or down to these vents. the vacuum line starts in the engine compartment right side, rear of the motor. it is a small black line about 3/16 diameter. has a TEE at the firewall about where the glove box is. Goes thru a rubber gromet at that point. Normally the TEE has a bad rubber fitting on it. the TEE also goes to an accumulator tank between the battery and the fender. Look for the TEE and inspect it. Pull the TEE apart and check that you have vacuum at that point. If so, you might have a leak on the backside of the control knob.--- the default position is to defrost (no vacuum) so you can defrost the windows if it fails.

thanks and i will try those fixes and go from there

cool let me know what you find