Foggy windows

[NoahSewal]

In my 74 dodge dart if the temp is 50 or below outside my windows fog up like crazy. Even with the heat off and everything. It's an AC car but the compressor and whatnot have been taken out of it. What would cause this? and when it's really cold outside steam will come out of my vents as well. what would cause this issue?

 

[RustyRatRod]

Bad heater core.

 

[A56]

If you have steam coming out of your vents, you should be able to smell coolant.

 

[Joey4speed]

Yep.
Agreed.
Interior moisture.
Looks like a heater core leak, as mentioned, the sweet smell of the coolant, or wet carpet on the passenger side are good clues.

 

[Treblig]

RainX