Air Coming thru Defrost Vents

[DZEE'S LX]

Make sure your heater core is working. You should be able to get cool or warm air out of the vents by changing the temp knob.

If that is OK get your head behind the dash, or you might have to remove some of the stereo and console plates, and look for the cable that is connected to your temp knob. The cable is connected to a lever that moves the mixing door inside the case. You should be able to move the door from stop to stop while you move the knob from cold to hot. The door is the mechanism that "decides" how much cold or hot air should flow to the vents/heater/defrost vents.

You might also find that the cold air draft goes away if you leave the fan on low and pick a vent or heat setting.

[84LX89GT]

chances are that if there's outside air coming in the fresh air flap door is leaking or damaged. There's a door that is vacuum operated (or cable/linkage depending on what year) that when you set your system on vent or A/C fresh air is allowed in, putting it in max a/c closes the flap to recirculate and further cool/heat the in cabin air.
The things i'd check is the seal around the steering shaft, see if any body plugs are missing (rubber grommets out of place, etc.) and worst case is take out the entire dash and heater plenum and check all the seals and fresh air inlet door.

[chrismc101]

I notice under the hood that someone disconnected the two hoeses that run to the heater coil for the car to run heat. What they did was take piece of tubing and ran the two hoses together. I pulled them apart and I noticed (antifreeze) maybe (I don't know) coming out of the hoses.

WHY would someone have these two hoses ran together in this nature? What purpose does it serve for them to be connected? I know I wanna have my heat running. If I unhook them from each other, which hose goes to which connection?

Somebody help me out, it's about to get cold in NC, even though FOXIE is put away for the winter & beginning restoration/modificaions for summer.

[DZEE'S LX]

Someone has simply bypassed the heater core. I can think of two reasons why this might have been done:

1. Heater core is leaking. You don't mention the year of your car but most fox body Mustangs are a PITA for replacing the core. You have to pull the console, instrument panel, and dash to get to the case that houses the core. This can be a significant and frustrating job, but it is definately doable if you have the patience for it.

2. Mixer door is not working right and someone wanted the air conditioner to run colder by having no warm air mixing when the A/C is on.

3. Someone told the previous owner that bypassing the heater core would produce an extra 50 h.p.

I'd guess reason #1 is the culprit but you can simply hook the hoses back up and see if anything leaks inside on the passenger side or under the car after running the engine at temp for awhile (possibly days). If your windows fog up easily that is also a sign of a bad heater core. You can also smell the antifreeze because the fan will fill the cabin with that lovely scent.

Can't remember which hose goes to which side.

Good luck!