hey everyone,

so i have a new jeep

99 cherokee w/ac

so i was driving on the highway for the first time today with the air OFF
no heat
no fan

my windshield was fogging above the defrost vents in front.

ive read that it could be my heater core....but wouldnt it be smoking or smelling if it was?

any info would be great!
thanks!

 

It does sound like you have a leaking heater core. If it's a small leak it won't blow out all of the steam and the smell. If you leave it as is you will be smelling it soon. Plus once it does start to leak more the carpet on the passenger side will start feeling wet, If not already.

 

You have water sitting in the HVAC box, it's kind of a normal thing for some vehicles. Condinsation from the A/C evaporator builds up and will make the windshield fog around the vent openings. You can make sure the HVAC drain is not plugged with a bunch of junk. It's the little black rubber elbow poking out of the firewall under the hood on the passenger side.

 

ill have to check the pass floor and see if its wet at all....

so if i just replace the heater core will that fix the problem?

 

can i just detach the elbow, and then clean it out? or do i need to buy new parts?

 

found the drain, checked it, it doesnt look clogged just from checking it on the outside, should i take the elbow off and try to see if its clogged farther up?

 

Couldn't hurt.

 

Did this fix your problem? I have the same issue and want to know if this was the magic bullet.

 

What's the relative humidity in your area. Might be you just need to run the defrost due to humidity...

 

it's just this one little spot just to the left of the glove box, but I am in Tennessee as far as relative humidity goes

 

Yes it's true, that drain is prone to getting clogged, but the OP said no fan or vents. A little water sitting in the HVAC box without the fan is highly unlikely to cause fogging on the windshield as stated. The steam is more likely to be caused from leaking coolant. Water won't be just sitting in there if the A/C (or defrost) hasn't been run recently. Of course without knowing the outside temperature, humidity, barometric pressure, altitude, position of the sun and moon, etc., one can only speculate.

I think we need some better diagnostic approaches here....OP, so what does happen when you do turn the fan on? What happens when you turn the A/C, or the heat on? Is this a consistent issue, or a one time thing? (That could rule out weather) What about your coolant level, do you have to add some every now and then?

 

Well the heat has completely stopped working, and get a strong odor of coolant in the cab. Given the gunk I found when a removed the radiator cap, I am gonna replace the entire cooling system.

 

Been there done that, twice. Thanks to stop-leak from the previous owner. I got lucky though & saved my heater core. Good luck!

 

thanks! Nice won't ride with me till the heaters working...

 

meant wife not nice...