2nd Gen Non-Engine/Transmission defrost problem

[Mhannink]

ok so i have an interesting issue that i need some help on. most mornings and it seems to not be dependant on tempurature. what happens is the windows will start to fog up so i kick on the defrost. what happens is my side of the window defogs but the other side along with the passenger window fogs up and wont go away. at first i thought it was coolant but im not loosing any nor do i smell any. the other thing i just noticed today was when i turn my fan speed switch to the white side and the temp all the way cold it only blows ambient. now i could be wrong on this but i seem to remember that when i would do this prior to the problem and as well in other trucks it would blow cold same as if you where to turn it to the ac side.

 

[PBJ2500CTD]

I would guess that your A/C is low on charge.

 

[Missouri Mule]

Do you have the selector switch turned to defrost when you turn the fan to the white side? If you have it on defrost or defrost/floor it should turn on the a/c compressor on either side.

Are you getting air out all of the defrost and the window vents when on defrost?

 

[Mhannink]

the ac blows nice and cold even when its 100 plu outside. also yes there is air out the defrost vents and the switch is on floor/deforst usually but sometimes on just defrost either way there is no difference the window just fogs up.

 

[PBJ2500CTD]

Hey, I thought the fog season was over by this time of year in the Valley. I spent more than a few years in a little town that was 20 miles to water and two miles from hell - Atwater. Actually, once we became desensitized to the (fill in the blank = heat, at least it was dry; depending on wind direction: the not so refreshing odors of the Foster Farms chickens#@$%!, and the almond husks fermenting, etc. , change the wind direction and the delicious smells of the Ragu 'sgetti sauce plant), it wasn't too bad.

Anyway, does the fogging last more than a few seconds or does it persist for minutes? I thought I understood from your first post it blew ambient air when on the cold position. But, since you say there is nice cold air but it is only fogging up, the charge should bo OK. It is normal for a few seconds of fogging to occur when initially turned to AC if it has recently been used. If it lasts longer maybe the drain for the A/C condensation is plugged up. Do you get puddles of water under the truck when you stop when the AC was on?

BJ

 

[Mhannink]

well normaly no there would not be problem this time of year but the weather here has been funky. not cold but cooler and very humid. anyways no the problem only happens when i turn the defrost on and yes it does last for some time. ill check the drain on the case and see if its plugged. anyone know where its at or what it looks like?

just to make sure things are clear the ac blows cold when i switch it to the ground side. its when i turn it to the white side that i notice it doesnt blow cold even though i think it would if you set the tstat to cold. i could be wrong on that but thats what i seem to remember.



as far as the area goes i know exactly where your at i live in modesto just a few miles north of atwater. the whole valley and really the whole state sucks. im chopping at the bit trying to get to nevada i think that state is much nicer.

 

[Missouri Mule]

If you crawl under the passenger side of truck near wheel well and look up at the firewall there is a small black plastic pipe (about 1 1/2 in, long) sticking straight out of the firewall ( use a flashlight even though i know where it is, it used take me 20 seconds to find it. Now there is a rubber hose attached to it. )



If you have your owner's manual handy look up the air/ heater controls see what it says. Since it has dual settings for the fan the compressor mite not come on when in the defrost if fan is turned to the white side(heater).

 

[PBJ2500CTD]

Now I have a silly question: Is it fogging on the inside, or the outside of the glass? I have experienced outside fogging on somewhat humid days up here in Washington State, as well as traveling through other moisture enhanced states, when the AC was on cold and in the defrost modes. When the outside warm, moist air meets the cold glass condensation will form on the outside of the glass under the right conditions. When it happened to me I initially thought it was on the inside until I tried to wipe it off with a rag and it didn't go away. The wipers took care of the windshield - but only temporarily. I had to turn some heat on to keep the condensation from forming, or turn the system to the floor or vent positions to keep the cold air off of the glass. If I remember my previous 97 Ram (early Gen 2) setup correctly, one side of the fan switch runs the AC and the other is the economy mode, no AC. You should find a short black hose coming out of the lower part of the passenger side firewall. Condensation should drip from the hose during, and immediately after AC use.
Another situation I have encountered recently in my '02 Ram is where the AC charge was low. There was just enough freon to eventually cool the air, but it took a while. So during the first several minutes of operation it would not de-humidify very well and caused fogging similar to what you described, especially on rainy days.
Left Atwater in '91... visited in '04... Didn't recognize the place; it had changed so much. Way too many houses and malls...
A friend of mine left Washington a couple of years ago to go to Nevada to head up a large motorcycle parts store. He loves it.

BJ

 

[DieselDoghouse]

PBJ2500CTD, not a silly question at all since I rehabbed my A/C I can completely obliterate my windshield just by refrigerating it!! Sometimes the obvious isn't obvious!!

 

[Mhannink]

no it is on the indside guys. i didnt really know that it could happen like that on the outside but it makes sense. anyways we will have to revisite this when the weather turns again so far no issues but the temps have come up to normal. who knows right now though could change tomorrow.