pquevill

When it drops below 20 or is damp outside I am developing a fog on the inside of my windsheild and more noticeable on the passenger side even with the defrosters turned on.

I checked the freon and I have plenty pressure or charge left. I have no drips or residue on the floor boards so I don't know if it is the heater core or not. Also up here in Chicago and MI it has been in the single digits and when I leave a driveway off centered if sounds like a windsheild cracking, but it is fine. I do have a rock chip in it and cannot find a noticeable draft or anything.

Anyone have any ideas?
Thanks
Pat

Totallyrad

Sounds like you could have a bad heater core or a leak in the cowl area. Pull the passenger's side floor mat back and see if the floor is wet. If it is wet, does it smell like antifreeze? Also see if there is any moisture on the bottom of the heater box.

jnicewan

if heater core is leaking the fog wont disappear, it leaves a film that will smear if you wipe it. your outside temp might be too low for the compressor to kick on in def mode so that might be part of it too. so...could be normal.

madhat

Usually, interior condensation is a sign that there is moisture in the cab. Do like T-rad said and peel back the carpet under the passenger side dash. Feel for wetness and smell for antifreeze. Could be a heater core. Someone did a writeup on how to do one not to long ago.

Good luck with that...

biododge1

can you wipe the fog away? if not I suspect the rock chip. It may have gone deep enough to allow moisture between the glass panes

pquevill

No moisture on the floor boards as mine was easy to check since I have rubber floors (no carpet). I also pulled out the blower fan since that was replaced this past summer and no moisture to be found along the hater box as well.

However I occassionally smell antifreeze in the cab area which has happened over the years. I do have to run and pick up a trailer in Elkhart and it will be an over all 8 hour trip so I'll keep checking.

The rock chip is deep with 2 small spikes. I just didn't get the glue in it waiting for the to crack over to the otherside and claim on insurance. Could be time to have the glass checked anyway after my trip.

Thanks for the responses!
Q

Sean Allan

This happened to me, and it turned out to the the thermostat. The truck would not warm up because the thermostat was stuck open, and this lead to the inability to heat up and get rid of the moisture inside the cab.

Check to ensure that your thermostat is opening at the appropriate temperature.

Sean.

jiMMyCTD

mine is dueto 2 rock chips. i dont drive it alot so i just put a thing of damprid on the console

justme-

FWIW I get that after a bad storm - no core leak of cabin leak- just from me getting in and out and leaving the windows open in a snow/rain storm. I find leaving the windows cracked open for a day or two usually equalizes the humidity.

Haulin_in_Dixie

Sounds like a bad heater core...

SIXSLUG

Mine does this too but it clears up quite quickly after warm up. Its wet up here and I figure its related to humidity, temp and dew point, combined with my wet gear and body in the truck. Sometimes the short trips don't get her heated up enough to move the moisture out of the cab.

Kurt

JoeCanuck

You could have water trapped in your heater system possibly caused by a plugged drain or a pinhole in your heater core.

One test is to thoroughly clean your windshield. If/when it steams up again, try to wipe it with a dry cloth. If it cleans up, it's water. If it streaks, it's antifreeze.

If it's antifreeze, it's probably the heater core unless you have gotten very lucky and you have a bad heater hose seeping into the cab.