91 f350 fogging up

[jimraelee]

Well its been quite a few months with my new truck. I have noticed that if I put the vent on it will start to fog up the side windows. Not the front like when you have a leaky heater core, but the side two door windows will fog a bit... Does the vent come thru the heater box on our trucks??? If so then maybe I do have some water in the box, but not real sure... I don't want to just pull the heater core for an inspection... but might have to. I don't see why the vent will cause fogging issues

 

[RLDSL]

If you're in western Oregon, I've known very few vehicles back when I lived up that way that didn't fog the windows with the vents unless you were either running the heat or the ac some to dry the air a bit

 

[masterbeavis]

Do your windows fog up if you breathe on them? It sounds like a dumb question, but if you are blowing warm air onto your cold windows, they will fog up till the glass gets heated enough to burn off the moisture. Have you tried any glass treatments, or any kind of anti fog stuff??

 

[jimraelee]

If you're in western Oregon, I've known very few vehicles back when I lived up that way that didn't fog the windows with the vents unless you were either running the heat or the ac some to dry the air a bit

yea you do have a point... but this was on a dry sunny day. My 97Olds van has ac on almost all the time, thats mostly do to the wife just leaving defrost on, and adj the hot / cold. You could be on to something though... I just hate leaving the ac/defrost on all the time... need to save all the HP for fuel economy I can.

nope no glass treaments... I don't know if I blew on them or not... I would assume so. This isn't just when I get in the truck and start a drive... Ive been driving for 30min or 1hr and switched over from defrost to vent. It was 60` outside one day this happened... I think there is some moisture in the vent system somewhere... heater box I'm afraid

 

[freebird01]

it only takes 10 minutes to pull the bottom of the heater box to look....(if its like the 80-86)

 

[jimraelee]

thx, I think I might take a look se today.... its my weekend.