HVAC mode won't change.

[Jeff K]

I rebuilt the HVAC mode switch two years ago.

I can hear the pfft air sounds when I turn it.

The mode does change, heat to AC, but the venting does not change. All comes out the defroster.

Any suggestions? I'm guessing a vacuum line got knocked off somewhere.

TIA
Jeff

[djdogbone]

Could be either the vacuum lines connected on the switch inside the dash or the rubber diaphragm inside the switch itself

[Jeff K]

Could be either the vacuum lines connected on the switch inside the dash or the rubber diaphragm inside the switch itself

Ok, thanks!