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As stated above. I have a ’96 Ford escort that is staying on recirculation mode when it is selected. You can clearly hear the blower motor get louder. If i remove the glovebox and look inside i can see the vent close and block outside air. Once I remove the control back from max a/c / recirc, it still stays closed.
If i pull the vacuum line to the control solenoid under the dash, it will release vacuum and the door will open and recirculation mode will turn off. The hvac is all cable/vacuum controlled. No fancy electronic actuators in there
Any ideas what the fix would be for this?
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If you remove the vac line at the selector/control
and it releases.sounds like the selector/control is
not switching or releasing.[quote=”college man” post=85280]If you remove the vac line at the selector/control
and it releases.sounds like the selector/control is
not switching or releasing.[/quote]I was thinking the same thing too.. but the weird thing is, when I pull the vaccum line from the vacuum control solenoid and turn on recirc. i can feel vacuum at the line. When I turn off recirc. and put my finger over the vacuum line, there is no vacuum present. It’s almost like something is not releasing the vacuum from inside the chamber of the vacuum control solenoid when the line is still connected.
Here is a vacuum diagram, if it helps.
So I did some more checks, and apparently whatever controls vacuum in the hvac control unit isnt always releasing the vacuum to the solenoid. There are some times where i can cycle it and it works perfectly 20 times in a row.. then i can try it again and it stays on recirc. Its no longer supplying vacuum, but it isnt releasing it either. So that leads me to believe that somewhere in between the control unit and the solenoid, it is holding vacuum.
I noticed a check valve in between there, but its quite hard to access without pulling the passenger side airbag. Would a defective check valve cause it to sometimes not bleed the vacuum?
A check valve is a one way valve. either vacuum is not being
supplied to the selector or the selector is not bleeding the
vacuum.I believe the check valve is there to hold vacuum on the
system.There might be something to the check valve theory. I’d like to point out however that when you select max AC, it will automatically put the system into recerc. This article may also be helpful.
http://www.ericthecarguy.com/faq/solving-automotive-hvac-problems
Keep us posted.
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