Diagnosing a HVAC vacuum issue on a Ford F53
The AC/heat is switching to the defroster under higher RPM conditions on my 2006 F53 chassis Damon. It actually seems to be doing it now under low throttle steady state conditions as well. Obviously...
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Actually... I just unplugged the hose from the accumulator where it connects to the dash controls. The baffle for the defroster immediately dropped and the line was hissing. The engine has been off for a half hour so that tells me the accumulator is fine. It would also suggest there's no leak elsewhere in the system which makes no sense.
Any thoughts?
It could be between the manifold and the accumulator but as near as I can tell that line is fine. The other vacuum line from the manifold goes to a device with an electrical connector on the driver's side valve cover. I'm guessing this is a valve related to the PCV system and if it was bad I guess it could deprive the whole system of vacuum but I don't want to go down that road without more information.
Thanks (again)!
Mike
Any thoughts?
It could be between the manifold and the accumulator but as near as I can tell that line is fine. The other vacuum line from the manifold goes to a device with an electrical connector on the driver's side valve cover. I'm guessing this is a valve related to the PCV system and if it was bad I guess it could deprive the whole system of vacuum but I don't want to go down that road without more information.
Thanks (again)!
Mike
