Clacking sound coming from under the dash and A/C is stuck on defrost

2003 FORD EXPEDITION
170,000 MILES • 5.4L • V8 • 2WD • AUTOMATIC
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NAMOR600
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  • 2 POSTS
For the last couple months i heard a clicking noise under my dash. And now recently my A/C is stuck on defrost. i checked the vacuum lines by the battery and fixed them and it still comes out the defrost.
Jun 14, 2021 at 4:49 PM
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JACOBANDNICKOLAS
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  • 110,175 POSTS
Hi,

There could be a vacuum leak after the engine area or the actuator itself may be bad. What I suggest is this. Locate the mode actuator and see if there is vacuum to it when changing from floor to defroster.

If you look below, I attached the directions for removal and replacement. The actuator is near the accelerator pedal. Check to confirm there is vacuum. If there is, chances are the actuator is bad.

Let me know what you find.

Take care,

Joe

See pics below.
Jun 14, 2021 at 9:55 PM
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NAMOR600
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Okay, i checked the vacuum motor and i pulled out the hoses and i had the car running and the A/C going and i didnt get any suction. It's an Eddie Bauer Edition i don't know if that helps.
Jun 15, 2021 at 3:32 PM
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JACOBANDNICKOLAS
  • CERTIFIED EXPERT
  • 110,175 POSTS
Hi,

If there is no vacuum, that is the likely reason it is in the default position, defrost.

At this point, if you have a vacuum pump, you could connect it to the actuator and see if by applying vacuum, you can change the direction.

Or, we need to determine where the vacuum is lost. I'm not sure if you have automatic temperature control or manual. I attached two pics below. The first is for manual temp control and the second one is automatic.

The pictures identify the connector on the rear of the control panel. Note that each vacuum hose is identified by a color. I need you to get up under the dash and locate the black vacuum hose to the controller. Disconnect it and start the engine. Is there a vacuum source provided by the black hose?

Let me know.

Take care,
Joe

See pics below.
Jun 15, 2021 at 9:49 PM