A/C and Vent blowing out of defroster

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bsmith4@hotmail.com - 29 Jun 2006 16:42 GMT

I've got a 1994 Mustang 3.8 and when I turn on the A/C or Vent, the air
blows out where the defroster air should blow (top of dash on
windshield). The defroster works fine, and the heater blows out on
the floor, but I can't get air to blow out the vents where the A/C
should normally blow out (directly at passengers).

What's the deal?

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JohnV@nn - 30 Jun 2006 01:23 GMT

The vent system is vacuum operated and if a line comes loose, it
defaults to defrost position as a failsafe. Check for a disconnected
vacuum line on the firewall next to hood hinge. Same thing happened on
my 93; vacuum line was hanging loose; when I plugged it back in, all
was fine.

Good luck,
John

> I've got a 1994 Mustang 3.8 and when I turn on the A/C or Vent, the air
> blows out where the defroster air should blow (top of dash on
[quoted text clipped - 3 lines]
>
> What's the deal?

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MicrosoftBob - 04 Jul 2006 20:37 GMT

> The vent system is vacuum operated and if a line comes loose, it
> defaults to defrost position as a failsafe. Check for a disconnected
[quoted text clipped - 4 lines]
> Good luck,
> John

I found the place where all the hoses connect near the hood hinge, but
none are loose. Now what? I assume one of the hoses is loose at the
other end, but which one to check first? And how? Do I need to
disassemble the dash?

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JohnV@nn - 05 Jul 2006 01:34 GMT

> > The vent system is vacuum operated and if a line comes loose, it
> > defaults to defrost position as a failsafe. Check for a disconnected
[quoted text clipped - 9 lines]
> other end, but which one to check first? And how? Do I need to
> disassemble the dash?

Hmm, if you don't see anything loose at the firewall, try to follow
each line coming out of that manifold and see where it leads; it may
have a break or split in it or it may be loose at the other end. Sorry
I can't be of more help; there are plenty here in the group who are
more experienced than me.

Also do a google search in this group for "defrost vacuum"

Good luck,
John

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