Hey all,

In my '95 E300 I have a terrible problem with the windows becoming completely fogged up when it is raining out. I can push the "defrost" button and I get full fan and full heat, but it really does nothing. If I let it blast for a solid 5 minutes it might make clear a about a quater of the way up the windshield, but otherwise I really can't see anything unless I grab a rag and wipe the sondensation from the windshield.

Has anyone had any experience with this problem, something just isn't right here. It's like too much mositure is accumulating inside the car. Something must be wrong - I can't imagine everyone has this experience.

__________________
'95 E300D ("Tank") - 231,000 miles
'79 240D ("Biscuit") - 197,250 miles (Sold)
'83 240D ("Ding-Ding") - 217,000 miles (Death by deer)
______________________________________

"Back off, man. I’m a scientist” ~ Peter Venkman

I don't think that is right. the window should fog up, if it's REALLY wet in your car, or if it's cold outside and it's raining. is your a/c running? the a/c removes moisture from the air, and the heater warms the window. you could have a leak in the airbox under your window, letting rainwater into your airstream...

Thanks.

In general the AC works in the car, but I don't know that it is running when the defrost button is depressed. When I press that button I get full heat at full blast at the windshield and at the side vents (not the center). What do others get? Is there actually supposed to be cold AC air blowing from some place? If I turn the AC on I get cold air, but there is no indiaction of AC when the defrost button is depressed.

If its raining and moderately cool outside, the windows fog up. Selecting the defrost puts full heat on at full blast on the window, which after a little while will clear a small area, but otherwise appears to make the situation worse as the condensation on the inside of the window actually seem to get worse to the point that water beads up. Clearly something is wrong.

At one point I thought maybe it was resulting from really dirty fresh air filters, so I replaced then, but that didn't really solve the problem. I will investigate the leak into the airbox.

__________________
'95 E300D ("Tank") - 231,000 miles
'79 240D ("Biscuit") - 197,250 miles (Sold)
'83 240D ("Ding-Ding") - 217,000 miles (Death by deer)
______________________________________

"Back off, man. I’m a scientist” ~ Peter Venkman

You hear the high fan and you feel the heat - How much air is moving out of your defroster vents? Sounds like a weak vaccum pod that is not opening the defrost chute all the way.

__________________
BENZ THERE DONE THAThttp://www.peachparts.com/shopforum/...c/progress.gif
15 VW Passat TDI
00 E420
98 E300 DT
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97 S500
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86 Holden Jackaroo Turbo D
86 300SDL
(o\|/o)

A quick visual check of the compressor clutch should clear up any uncertainty.

No. The a/c will be more than overwhelmed by the heat when the engine is at normal operating temp. The a/c evaporator is intended to serve as a dehumidifier when defrost is selected. The effect is far from immediate.

In short - a buttload. There is adequate heat being pumped onto the windshield, but it really has very little effect. Or, by the time it has been on long enough to produce any effect, you are nearly ready to die from heat exhaustion - this is not a joke.

__________________
'95 E300D ("Tank") - 231,000 miles
'79 240D ("Biscuit") - 197,250 miles (Sold)
'83 240D ("Ding-Ding") - 217,000 miles (Death by deer)
______________________________________

"Back off, man. I’m a scientist” ~ Peter Venkman

Thanks, right, I will check the compressor. I never knew the AC was part of the defrost process.

__________________
'95 E300D ("Tank") - 231,000 miles
'79 240D ("Biscuit") - 197,250 miles (Sold)
'83 240D ("Ding-Ding") - 217,000 miles (Death by deer)
______________________________________

"Back off, man. I’m a scientist” ~ Peter Venkman

"Defrost" is intended to melt ice. You might be better off using the a/c in the bilevel mode for defogging.

It sounds like the drains might be clogged and water standing in your HVAC unit.

__________________

Gone to the dark side

- Jeff

oooh, good one!

__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

Hmmmm. Interesting. I am on my way to check it out. Thanks.

Oh . . . and replace my radiator, which developed a nice leak this week.

__________________
'95 E300D ("Tank") - 231,000 miles
'79 240D ("Biscuit") - 197,250 miles (Sold)
'83 240D ("Ding-Ding") - 217,000 miles (Death by deer)
______________________________________

"Back off, man. I’m a scientist” ~ Peter Venkman

bad vac pod on the recirc flap. thats why it doesn't clear even though its on high. its just recirculating the moist cabin air.

Would it not be recirculating through the cold evaporator coil?

I think it is most likely a lack of the compressor coming on. It has to have that to "de-fog".
I use all mine on the bilevel ac setting when it rains. First, the super high fan speed annoys me, second I seldom want full heat.
What a stupid system they had for far too long!!

__________________
Jimmy L.
'05 Acura TL 6MT
2001 ML430 My Spare

Gone:
'95 E300 188K "Batmobile" Texas Unfriendly Black
'85 300TD 235K "The Wagon" Texas Friendly White
'80 240D 154K "China" Scar engine installed
'81 300TD 240K "Smash"
'80 240D 230K "The Squash"
'81 240D 293K"Scar" Rear ended harder than Elton John

Well guys, it looks like the compressor is not engaging. I did also check the drain and although one side drain was a little plugged, the others were clear. Now to figure out why the compressor is not engaging.

I have to agree though, I don't really care for the "defrost" in this car. I guess it really is just for clearing ice. I went with the bi-level air tonight and it worked alright. I'd like to see how the defrost works when operating properly. I suspect it will still drive me nuts with the blasting of the hot air.

__________________
'95 E300D ("Tank") - 231,000 miles
'79 240D ("Biscuit") - 197,250 miles (Sold)
'83 240D ("Ding-Ding") - 217,000 miles (Death by deer)
______________________________________

"Back off, man. I’m a scientist” ~ Peter Venkman