My A/C will be on full blast while I'm driving and when I hit the gas full throttle, it will stop blowing. Then when I let off the acclerator, it will go back to normal. Any thoughts?

Do you mean that the blower quits blowing OR that the center vent goes closed durning acceleration?

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

I think it is the blower. But I will check for sure. What do you think the problem is either way? (Vents or blower?) Thanks a million!

If the blower actually stops working, I'd suspect the brushes are worn out.

If the vents change (to floor and/or windshield), you have a vacuum problem, most likely a bad "Y" connector next to the booster or the line to the reservior. Could also be a bad check valve allowing the vac to drop when it shouldn't.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Peter:

Thanks for your insight on this issue.

My 126 is blowing gobs of air out the defrost side vs. the vent side while on vent. I do realize I have issues with components within the dash.

As mentioned above, my center vents stop blowing air when accelerating as one does when entering the highway.

Out comes the glove box.......and a peek at the Y.

Onward.

__________________
Mike Murrell
1991 300-SEL - Model 126
M103 - SOHC
"Fräulein"

Is dissasembling the dash required to resolve both of these issues? Also on a side note...do you know what kind of refrigerant my 98 clk 320 takes? And how much? Thanks a million!!

After further investigation, when I go full throttle the center vents close and the air begins to come out of the defroster. Any ideas guys?

The check valve on the AC system supply vacuum line is bad. This will drop the vac when manifold vac drops at wide open throttle, so the flaps all close and you have defrost only.

The other possibility is vac leak in the AC system itself.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Sorry if this questions sucks but....where exactly is the ac system supply vacuum line? Thanks

Can you just get that check valve anywhere like a PepBoys or AutoZone type place or is it special to MB's? I think I need one since when I floor it I sometimes get my dash vents to open, but not always! I just recently put in a new heater core and checked all vacuum connection in the dash and all are good now. I did have one line that was off but it is now reconnected. I have also fixed all bad connectors under the hood and double checked the resvoir. This is on my 190E. So it is strange that I now have this issue that I noticed this morning when I had floor vents selected and the defrost ones opened a few times while accelerating. I am assuming it is the check valve since that is the only thing I have not replaced as of yet. And my Y's are all good! So if I could avoid going all the way to the Stealer for a check valve and could stop at your friendly parts store I would much rather do that! Is there anything special about the check valve or are all pretty much the same?

Thanks,

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~Jamie
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2003 Pewter C230K SC C1, C4, C5, C7, heated seats, CD Changer, and 6 Speed. ContiExtremes on the C7's.

1986 190E 2.3 Black, Auto, Mods to come soon.....