blend air door broken?

[wildcatsua]

1999 camry 126k. A few days ago something happened that now the AC is always stuck on the face position. Turning dial to face/floor, floor, floor/defrost, or defrost has no affect on where the air comes out - it's always 100% out the front vents.

I took the switch out and checked with my fluke. Although the continuity between certain pins does not match what my Haynes manual says it still moves when the switch is turned. Conclude switch is OK.

I guess there's something called a blend door that is motor controlled?

Any ideas are appreciated.

Thanks!

[wildcatsua]

A little more research leads me to believe the motor for this is actually called:

SERVO SUB-ASSY, DAMPER(FOR MODE)

Anybody have any idea how to replace? Can it be changed without pulling the dash?

Thanks for any help!

[somick]

On some cars servo motors are controlled by vacuum. Make sure you do not have a vacuum leak.

Have you checked with your car's FSM at www.carystuff.com?

Sam

[wildcatsua]

Thanks but I think because the "Mode" switch is electric that it goes to an electric motor. Also, never heard a vacuum operated device called a "servo".

I'll keep checking.

Any other ideas?

Also, is there a typo in your link to carystuff.com?

thx

[Brian R.]

See the link at the sticky post at the top of this forum for your service manual.

[wildcatsua]

Thanks! Got the manual.

I checked the mode switch as instructed for continuity across certain pins as shown on page AC-85. This diagram is also in my Chilton's. I didn't get the results shown. But even when I plugged a jumper across the other side of the connector the mode didn't change. I assumed the Chilton was wrong but here is the official manual with the same pin diagram.

The switch is easy to replace but I don't want to waste money on something that's not broken.

Any ideas?

thx