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Re: AC Blows on Defrost first
> my 87 5KSQ blows air out of the defrost vent when I run it for the first
> each day. After that All seems Fine. Any Ideas.
If you're concerned about flap position (and not about the fan), then ...
Mostly normal. Vent flaps are operated by "motors" that use vacuum. With no
vacuum, the resting position of all flaps/valves is
fresh-air/defrost/heaterValveOpen. So, when you start up, vacuum needs to
build up before the flaps can move.
Is there a vacuum reservior for this purpose? If so, then you might have a
slight leak somewhere.