1997 grand marquis air wont switch from vent to any other setting.

4 posts 3 contributors 1,141 views

mgm97OP

Member since Aug 2009
3 posts
Broken Arrow, OK, USA

Sep 2, 2011 at 5:34 AM

Latetly after shutting my car off I noticed what sounds like a vent door inside the dash moving.I checked the a/c/heating system and noticed that the air only comes out of the vents,it wont swtch to defrost or flloor settings when those are selected.Any ideas?.

wizzard1222

Member since Jan 2011
139 posts
Ballwin, MO, USA

Sep 2, 2011 at 6:45 AM

Check for vacuum leaks from hoses that might be old, cracked or dislocated from any ports...

Remember to check your fuse box....!!!!

Hope that's a starter....

edited Sep 2, 2011 at 6:46 AM

jdmeaux

Member since Jan 2009
525 posts
Lafayette, LA, USA
1 vehicle in the registry

Sep 2, 2011 at 8:07 AM

Over the years the vacuum hoses start rotting out and leaking, and dust and junk start to clog the contact areas that the vent doors touch, causing leaks. If worst comes to worst, you may have to pull the dash to get the plenum box to clean it out. MAJOR PIA! But it can be done. Just get a shop manual like Haynes and take your time, being sure to take pictures (if you have a digital camera) or sketches of were every goes. And DON"T FORGET TO LABEL all parts.

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It's just a SUPER-DUTY Mustang GT Sedan. 198K miles and still rolling HARD.

1997 Crown Victoria P71 SVT *** ex-US Marshall service (the CAR)
STOCK?? I bet it was modified.

13.26 @ 107.24 MPH 1/4 mi w/ me, tools, & full tank of 93 octane

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mgm97OP

Member since Aug 2009
3 posts
Broken Arrow, OK, USA

Sep 2, 2011 at 9:55 AM

After I shut the car off I can hear hissing from under the dash,the moise appears to be coming from the L/H side oh the dash.Is this normal?

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