Help!!! A/C out of defrost vent only

[SIC FIDDY]

So here is my problem guys. My A/C is working but only through the defrost area below the windshield. I am unable to switch from the vents or floor areas. My high/low knob is working correctly on the HVAC panel but I cant switch up the direction that the air is going. Do you guys think that the fan motor isnt working anymore or something? Ive got no ideas here and its hot as hell outside!! Any help would be awesome

 

[Renegade]

could be the actual ducting

 

[SIC FIDDY]

Yea but for everything to just stop working all of a sudden?

 

[Renegade]

the vacuum mechanism that controls the doors in the ducting?

 

[Tommy]

It's more than likely the ducts. As you switch the knob, the ducts open and close. I believe they are vacuum activated.

 

[Renegade]

same thing happened in my Cherokee when i had it, and thats what it was

 

[SIC FIDDY]

It's more than likely the ducts. As you switch the knob, the ducts open and close. I believe they are vacuum activated.

So do I look for a vacuum leak then?

 

[Tommy]

Yeah, try the easy stuff first that usually tend to be the over looked. I have no idea what the configuration is for your car, but a Chiltons manual may come in handy

 

[Mustangcwo]

OK everyone, here is the secret link that makes me look like a shinning star. Use it well!!!
http://www.veryuseful.com/mustang/tech/engine#Diagrams

There will be a master line that goes from a check valve in your engine compartment through the firewall. The rest or the vacuum line is located behind the dash. Good luck with this one.

 

[dope3]

most likey its out side near the intake i had this one happen top me it was the red vaccum lines were old and cracked good luck

 

[kakarote]

Ditto on vacuum. If possible , remove front panel and pull switch assy. out. listen for leak.
Good luck..!! Also ck to see if door panel in air box is moving. should be a vac. line on a vac. module on side of box.
Again .. good luck!

 

[Foxman]

hey if your not busy tomorrow charlie... bring it by and we can take a good look at it... if all else fails i know i can rig it to blow out the vents only...

 

[Renegade]

strap a little fan in there like you see in drag cars :rofl:

 

[wickedstangs]

So here is my problem guys. My A/C is working but only through the defrost area below the windshield. I am unable to switch from the vents or floor areas. My high/low knob is working correctly on the HVAC panel but I cant switch up the direction that the air is going. Do you guys think that the fan motor isnt working anymore or something? Ive got no ideas here and its hot as hell outside!! Any help would be awesome

Did you just install a stereo or move the AC in anyway? If you did there is a wire that hooks up to your ducting When you switch the AC on it opens it.

 

[SIC FIDDY]

Did you just install a stereo or move the AC in anyway? If you did there is a wire that hooks up to your ducting When you switch the AC on it opens it.

Nope, last time I had that area apart was during the tach install. Everything checked 4.0 up until a few days ago. I will re check that wire though

 

[Foxman]

you busy tomorrow charlie?

 

[Sinful]

pop the hood, look at the brake booster and above there's a vacuum tree with about 3-4 lines. there's one plastic line that goes from that tree all the way the heater core lines, inspect it.. it's probably broken/leaking.

 

[SIC FIDDY]

you busy tomorrow charlie?

Yea gotta work tomorrow. I can stop by Thursday though