Odorless Steam from Defrost vents when Heater is on

[Rossi]

Every time I turn on the Heater or Defroster.... odorless Steam comes out of the Defrost Vents and Fogs up the Windshield . I've had Heater Core issues in the past with other Cars but those leaks always smelled of Coolant. Saw something on the internet saying that a Drain Hole could be clogged? Any ideas?

[Rich G.]

I'd still bet on the heater core starting to leak.

[Burdar]

Are you talking about an A/C box or a NON  A/C box?  I've never messed with an A/C box but a NON A/C box doesn't have any "drain" to the outside.  I'd pop off the clips and remove the inside cover.  Then you'll be able to tell if there is any debris(leaves exc...)inside.  You'll also be able to see if the heater core is leaking.  It could be a very small "weep" and you'll see some antifreeze discoloration...not standing coolant inside the box.

[JS29]

Are you talking about an A/C box or a NON  A/C box?  I've never messed with an A/C box but a NON A/C box doesn't have any "drain" to the outside.  I'd pop off the clips and remove the inside cover.  Then you'll be able to tell if there is any debris(leaves exc...)inside.  You'll also be able to see if the heater core is leaking.  It could be a very small "weep" and you'll see some antifreeze discoloration...not standing coolant inside the box.

Check the carpet as well.   

[Rossi]

It is an AC Heater Box. What Clips and what cover...is it accessible from under the Dash?  I have no water leaking on the Passenger side.....I have had Heater Core issues on another later model car but it always smelled real Strong of Coolant.....I'll poke around under the dash to see what cover yer talking about.

[1 Wild R/T]

Being an A/C box means it doesn't come apart easily..... Does the A/C actually work? Cold air in the summer?  Cause if it doesn't you can forget about the drain...  But if it does the drain is possible, not likely but possible and a heck of a lot easier that the alternative...

[screamindriver]

There should be a drain with a 90* rubber elbow that lets the water out but keeps debris from entering..Make sure that the end of that elbow is open sometimes it seals itself and traps the water in the heater box...The elbow is located on the engine bay firewall near the blower motor ..

[screamindriver]

Found the firewall A/C detail..

[Rossi]

So it's the heater box Drain Hole....got it! Thank you. I'll check it this Weekend

[Mopar5]

On defrost the AC and heater are both on and the AC evaporator is condensing moisture out of the air to get rid of it.. If the moisture cant drip off and drain away from the evaporator then that could cause it. especially since your not smelling coolant .