My a/c will blow out ice cold only on the defrost setting for about 1min. Then it will start blowing out warm air. Then i shut it off, wait 1sec and hit defrost again and it immediately blows ice cold air again. Then after about a min starts blowing warm. What could be causing this?

does anyone know? could someone shed some light on this issue.

On the defrost setting shouldn't it be blowing warm air onto the windshield ?
Is your car engine warmed up at the time of this event ?
Does the AC work properly in the MAX COOL setting ?

__________________
1980 240d ,

chain elongation, cam marks reference:
http://www.peachparts.com/shopforum/diesel-discussion/10414-help-i-need-check-stretch.html

http://www.peachparts.com/shopforum/diesel-discussion/305365-9-degrees-chain-stretch.html

evap fin cleaning:

http://www.peachparts.com/shopforum/diesel-discussion/156207-photo-step-step-post-showing-w123-evaporator-removal-1983-240d-1982-300td.html?highlight=evaporator

A/C thread

http://www.peachparts.com/shopforum/diesel-discussion/297462-c-recommendations-mb-vehicles.html

Check the following link.

Troubleshooting the Mercedes-Benz 190 Tempmatic ACC Climate Control System

Thank you, I will check that out

How about answering my questions ?

__________________
1980 240d ,

chain elongation, cam marks reference:
http://www.peachparts.com/shopforum/showthread.php?threadid=10414

http://www.peachparts.com/shopforum/diesel-discussion/305365-9-degrees-chain-stretch.html

evap fin cleaning:

http://www.peachparts.com/shopforum/diesel-discussion/156207-photo-step-step-post-showing-w123-evaporator-removal-1983-240d-1982-300td.html?highlight=evaporator

A/C thread

http://www.peachparts.com/shopforum/diesel-discussion/297462-c-recommendations-mb-vehicles.html

The car does not have to be warmed up, It is on the max cool setting. For some reason It will only blow cold on the defrost setting for about a min

ok... your first post sounded like you were talking about its performance in the defrost mode... .
not max cool...
How long will it blow cold air in the max cool mode ?
I think you have a ' routing ' problem... check your vacuum and the doors which direct your air to your various vents...

__________________
1980 240d ,

chain elongation, cam marks reference:
http://www.peachparts.com/shopforum/showthread.php?threadid=10414

http://www.peachparts.com/shopforum/diesel-discussion/305365-9-degrees-chain-stretch.html

evap fin cleaning:

http://www.peachparts.com/shopforum/diesel-discussion/156207-photo-step-step-post-showing-w123-evaporator-removal-1983-240d-1982-300td.html?highlight=evaporator

A/C thread

http://www.peachparts.com/shopforum/diesel-discussion/297462-c-recommendations-mb-vehicles.html

It will blow cold for around 1 minute then turn warm, I shut it off and I immediately push the defrost button again, then it blows ice cold instantly then lasts for a minute then turns warm. This is the cycle

What happens if you put it on max cool and leave it there.. ?

When you put it into defrost mode ... it is supposed to be warm....not cold .. so are complaining that it takes a minute to turn to warm... that getting to warm should be faster ?

__________________
1980 240d ,

chain elongation, cam marks reference:
http://www.peachparts.com/shopforum/showthread.php?threadid=10414

http://www.peachparts.com/shopforum/diesel-discussion/305365-9-degrees-chain-stretch.html

evap fin cleaning:

http://www.peachparts.com/shopforum/diesel-discussion/156207-photo-step-step-post-showing-w123-evaporator-removal-1983-240d-1982-300td.html?highlight=evaporator

A/C thread

http://www.peachparts.com/shopforum/diesel-discussion/297462-c-recommendations-mb-vehicles.html

I do not know what is your problem but I can give you some pointers. Check out post #9 in the following post if the compressor stops after a 'fix' period of time. I fixed mine.

W124 - stumped by the Climate Control Unit

This is what I recommend you to do:

1) Set A/C on ( do not use defrost ) and check whether the compressor engages or not.
2) Check whether compressor times out and quits. If it does then measure the time and start the car again and repeat.
3) If it times out like clock work then it is the thermostat inside the evap box.

I think the A/C system principle is all the same for W124, W126 and W201. Give it a try and it costs nothing.

4) You can also try to by-pass the Kilma. I can make you a by-pass Kilma which by-passes everything except the freon low pressure switch. This will give you an idea whether the cut out is caused by belt slipping or engine too hot.

Good luck.

__________________
Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.

alright, with the temp set at max cool and everything set to a/c. cold air only comes out when the defrost button is used. cold air will only come out for about a minute. If I use any other buttons no cold air at all.

Ok... go see if the url referenced will help..
but if you have cold air at any time... it sounds like the flaps in your climate control system are not sending the air to the vents correctly..
in defrost it should be warm PLUS the ac being on to dehumidify the warm air...so that part may be correct...
but you should be able to get that cold air with AC max cool on...
have you done anything to the vacuum system... or any other mods lately....?

__________________
1980 240d ,

chain elongation, cam marks reference:
http://www.peachparts.com/shopforum/showthread.php?threadid=10414

http://www.peachparts.com/shopforum/diesel-discussion/305365-9-degrees-chain-stretch.html

evap fin cleaning:

http://www.peachparts.com/shopforum/diesel-discussion/156207-photo-step-step-post-showing-w123-evaporator-removal-1983-240d-1982-300td.html?highlight=evaporator

A/C thread

http://www.peachparts.com/shopforum/diesel-discussion/297462-c-recommendations-mb-vehicles.html

You need to check that. If COMPRESSOR only engages when you press for defrost button then your Climate Control unit probably went south or you have a thermo sensor believes the cabin is AT temperature. I have nothing more to add.

__________________
Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.

Thank you guys for all your help, I have not done anything to the vacuum system. The vacuum system actually works great. I'm going to swap ccu with a used one I have.a I will let you guys know what happens.