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Chuck, ASE Certified Technician
Category: Ford
Satisfied Customers: 2100
Experience:  33 Years Experience,Ford Senior Master,ASE Master,L1 Advanced Engine Performance
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2002 Ford F150: Crew..Electronic..Climate Control..the heat/AC..vents

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2002 Ford F150 Super Crew with Electronic Climate Control. The problem is that the heat/AC will only blow out the dash vents. So...I've ruled out the blend door, as my temp. will control fine. I've ruled out a broken vacuum line, as I tested them today with a vacuum pump and they hold at 20" while the truck is at idle and I loaded them to 20" and they held for as long as I was sitting there watching the gauge. I took the EATC unit out of the dash, took the vacuum air plenum off the back and tested the lines from there. I want to "jump" the EATC unit and close the mode door with the vacuum pump and move it to defrost, but I don't think I'm doing it right as it will move the mode door.

Can you tell me how to test this...or if you have any ideas on what my problem is. I'm leaning toward a broken mode door. The part dept. at the Ford dealer says he has history of all three of the actuators going out. Last...should I be able to manually move the actuators and close/open the doors?
Is the vacuum supply and reservoir ok?
Customer: replied 7 years ago.
Good question, I don't know that. I only knew to test the actual vacuum lines. How should I check that?

Defrost is the default position(no vacuum). The reservior is located next to the battery, you would have to remove the battery to replace it if bad. Here is a pic of it.




Make sure you have vacuum supply to it from the intake manifold and then make sure you have no leak there. It supplies the controls on the black hose.

Here is the vacuum schematics



ItemPart NumberDescription
118A318Vacuum control motor- panel/defrost door
2- Panel/defrost door (full vacuum position)
3- Defrost airflow
4- Side window demister airflow
518B545Temperature blend door (full heat position)
619860A/C evaporator core
7- Air inlet door (full vacuum position)
8- Outside air inlet
918A318Vacuum control motor- air inlet door
10- Recirculated air inlet
1119805Blower motor
12- Vacuum to emission control
13- Vacuum from the engine intake manifold
14- A/C vacuum check valve (part of 19C828)
1519A566A/C vacuum reservoir tank and bracket
1619980Electronic automatic temperature control module
1718476Heater core
18- Panel/floor door (full vacuum position)
19- Floor airflow
2018A318Vacuum control motor- panel/floor door
21- Panel airflow






ItemPart NumberDescription
1- Not used
2RedPanel/defrost door
3BluePanel/floor door
4BlackSource vacuum
5WhiteAir inlet door
6YellowPanel/floor door



If the reservior is good and you have a good vacuum suply to it and also to the control head then your problem will be the control head itself.

Customer: replied 7 years ago.
Should I be able to manually move the mode doors by grabbing the rods sticking out of the actuators and push/pulling them to move the doors? I wanted to rule out the actuators being bad.
If you are talking about the doors that move with a vacuum motor then yes.You should also be able to move doors with your vacuum pump,just use the diagram I sent you for the doors.

Maybe this will help


Vacuum Applications Chart-Electronic Automatic Temperature Control

Switch PortColorFunctionManual Override Selector Buttons
2RedPanel/ defrostNVVVVNVNVNV
3BluePanel/floor (partial)NVNVNVVVVNV
5WhiteOutside/ recircVVNVNVNVNVNV
6YellowFull floorNVNVNVNVVNVNV

V = vacuum

NV = no vacuum

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