Minor problems but annoying(A/C, sunroof, passenger window)

1994C220 · #1 08-03-2001, 12:01 AM

Hello everyone. This site is great, and I spent hours reading all the posts. First and foremost, I think that there is no substitute for a Mercedes. I bought mine used 4 years ago with 80K miles, and picked it over a 95 Acura Legend with only 42K miles because after test driving both, I couldnt see myself driving another car....

Well, after 4 years, and relatively no problems, those little things are starting to annoy...

Most importantly, the A/C. The AC blows out nice and cool, except that after the car warms up, the middle vents will cut out, and the air is diverted to the defrost vents...And they will come back on intermittently especially when Im at a stop light....but, as soon as I press the gas, they go out...Please help me with this problem(Im in Austin, and we have had 21 straight days of 100 plus weather) I had this similar problem last summer, and when I took it to the shop, they replaced the A/C filter, and it fixed it....needless to say, I replaced the filter this year, but it didnt help.

Secondly, the sunroof. It always sticks when it gets 3/4's closed, and when its closed, the pop up option doesnt work....any suggestions?

Lastly,(i promise)...The passengers side window...when you roll it down, it is loose, and opens crooked, like its not attached correctly to the remote arm....is it easy to get to? Or should I have the dealer fix it?

Thanks in advance. Im sorry for the long email.

#2 08-03-2001, 09:50 AM

The vacuum outlet control line to the A/C duct work may have a slight kink in it somewhere. I am trying to chase down the same problem in two vehicles in my garage at this time, also (vette and an SL).

I can't help you with the other problems. Good Luck.

David C Klasse · #3 08-03-2001, 03:15 PM

Alright, I'd love to help you with your problems... but they don't sound too common!

A/C... I agree with southern son, could be a vacuum problem.

As for the sunroof, what do you mean it gets stuck 3/4 of the way closed? Does it go real slow the last 1/4 of the way? Or does it completely stop? And the pop up feature will not operate...
I would replace the sunroof switch and grease the sunroof rails.
Hopefully that will clear up your problem.

Your passenger window must be off track or something. The only way to find out the problem is to take off the door panel and investigate. The door panel is not too hard to remove.

Good luck and keep us posted.
:p

1994C220 · #4 08-03-2001, 03:15 PM

Where do I find the vacuum outlet control line? Would I look through the inside, under the passenger compartment by the AC filter, or do I have to go from the hood?

I was reading that problems with the relays would make the default setting go to defrost, which sounds like what my car is doing. Because it works fine for the first 5 or 10 min, and the AC blows out nice and cold, and the middle vents work fine....but after about 10 min, it begins acting up again, and it will until you turn off the car. You can start the car again, and the AC will work fine for another 10 min...If anyone knows what I can do, please let me know...thanks.

1994C220 · #5 08-03-2001, 03:29 PM

Thanks David for the reply. Can you or Southern son, or anyone for that matter help me with where to start looking for this vacuum problem? I am an amateur mechanic, and I do mean amateur...but I love working on my mercedes....Any help is appreciated on this AC problem.

The sunroof, the motor works fine on the sunroof, and it doesnt slow down, but it gets stuck at the same spot every time, and you have to reverse and then go forward again and it closes fine....when you close it completely, from the inside, the corner flap raises as if it is popping up,(could it be off track?), and when you hit the pop up button, it doesnt do anything(not even noise).

I will try to grease the rails this weekend to see if that alleviates the problem.

I will also attempt to take the door panel to investigate the window.

Thanks,

David C Klasse · #6 08-03-2001, 04:15 PM

Quote:

Originally posted by 1994C220
I am an amateur mechanic, and I do mean amateur...but I love working on my mercedes....

I am the same way! I would not have the slightest idea where to start looking for the vacuum problem...
As for the sunroof, I would get above the car and see if you can find any obstructions or anything? And definitly grease the rails (you should use Mercedes-Benz grease).

Try closing the sunroof using the convenience feature (key in door) and see if it closes any differently. This will help determine if you switch is *possibly* the culprit. Doesn't sound like it, but we might as well rule out all possibilities if you're stumped!

Good luck!

Also, the door panel needs 4 screws removed:
1 on trim by door latch,
1 on the bottom below the speaker
1 under the armrest
1 behind the door handle (must pop out plastic backing with flathead)
Then the rest is snapped on... you need to release these and then pull slightly upwards before pulling out.

#7 08-03-2001, 04:57 PM

Regarding the A/C changing modes on you after warm-up, I think there may be something else for which you should look. As most systems on M/B vehicles use the same type set-up I will tell you of something on my little '81 380SL. In the middle of the dash upper cover, between the middle outlet ducts there is a small vent like little sensor. Under the dash pad one will find a small duct that leads off to the right with a flimsy type little sleave. The purpose of this sleave is to send a good average of ambient cabin temperature to the sensor for temperature regulation. You may be able to remove the glove box (should not be too difficult) to look over at the sensor and see if the small sleave is in place. If not, reconnect or if it is badly deteriorated you can just put on some clear plastic tubing and lead it over to just under the glove box somewhere. This will enable the environmental control to function properly (hopefully). Don't get flustered, everything is an education.

1994C220 · #8 08-03-2001, 05:28 PM

Thanks, my wife just explained we will be in Houston this weekend, so it looks like I will have to wait until late Sunday or Monday to try these tips...I will let everyone know how it goes.

By the way, I wanted to know if anyone had a set of C class alloys they would like to sell or trade. It seems my car has the alloys from a SL...I bought them new OE for 480 for the set....and would like to get the 8 hole wheels instead...

I am also saving up for a 98 or 99 E420, so I will have my car in the classifieds postings hopefully as soon as possible.

Thanks,
Carlos

1994C220 · #9 08-06-2001, 04:49 PM

Ok, I spent last night looking for anything out of the ordinary with the cooling system. I am afraid to say that I was unable to find anything that looked wrong with the AC system.I was not able to get in thru the glove compartment, it looks like it is one piece with the dash, so I was not able to find anything inside that might be responsible. If anyone out there has a C-class and knows how to get back behind the dash, let me know.

So the AC problem is still there, while I was messing with it last night, I did notice that the none of the airflow buttons seem to work(although the red led light is on when you push it), and the recirculate button doesnt seem to work. It used to kick the AC in high gear when you pushed it, now, its doesnt do anything...could this be related, or just a symptom to the problem?

I wasnt able to get to the window yet, but I did grease down the sunroof slides, and the sunroof doesnt stick anymore!!!! The pop-up feature is still not working, but at least the sunroof closes on the first try now.

David C Klasse · #10 08-06-2001, 05:48 PM

Ok, for the A/C, we can find out exactly what codes you are getting. There is a procedure to pull AC codes from the PBU, via N22 read-out. This should help you figure out exactly what is wrong. Have a pen and paper handy.

1. Turn key to ignition position 2 (start mode, but do not start the car.)
2. Set the climate control to LO.
3. Simultaneously, press and hold the REST button and (front) DEFROST for atleast 2 seconds, or until dIA appears.
4. Press AUTO to go through each step/code. When numbers appear, record it, and pretty AUTO to get to the next one.

Once you have recorded all of the numbers, post them back on here and I will tell you what they mean. And feel free to delete them when you are finished, this way you can check back and see what codes are actually the problem. (IE... a code could have appeared once 3 years ago, and never came back. It will help us narrow down the problem.
GOOD LUCK!

1994C220 · #11 08-07-2001, 08:54 AM

Thanks David. Here are the codes I got from the display...I erased them once and they all came up again the second time I did this.

28°
62°
60°
80°
82°
10°0

I am not sure what these mean, but I hope each one is not a separate problem.

Thanks for your help, my friend thought that getting the codes right off the A/C was the coolest thing.

Carlos

David C Klasse · #12 08-07-2001, 02:39 PM

Glad you were able to retrieve the codes, many time people have trouble with it... I can tell you another cool trick too!

28: Refrigerant Pressure Sensor (B12), CAUSE: Short Circuit. Intermittent.

60: A/C Compressor, Electromagnetic Clutch (A9K1), CAUSE: Short Circuit. Intermittent.

62: A/C Compressor, Electromagnetic Clutch (A9k1), CAUSE: Short or Open Circuit. Intermittent.

80: Switchover Valve Block (Y11/3), Tempering Flap, CAUSE: Unknown. Intermittent.

82. Switchover Valve Block (Y11/3), Tempering Flap, CAUSE: Short or Open Circuit. Intermittent.

100: Switchover Valve Block (Y11/3), Footwell Flap Long Stroke (80%). CAUSE: Unkown. Intermittent.

60 and 62 seems to be very similar... I am not sure what the difference between the two causes are or why. Look in the forum and you will see a post I started recently (A/C Diagnostics Codes). 60 and 82 are recurring for me also. They will come back after a day or two. I am still in the process of trying to understand what these explanations mean. I am kind of in the dark on that aswell. Now we just need SteveBfl to come along and help us out from here! I think that the "flaps" are related to the opening and closing of different vents, or the distribution.

You can also do other things with you A/C unit. With the car on and climate control on, press and hold rest for 5 seconds... you will then see the number "1" flashing across the screen and another number flashing (in cabin temp), they should be flashing between the two. Number 1 is the temperature inside the car. TO scroll to the other modes press the ARROW UP ('defrost'), and ARROW DOWN (feet). I can get you my list later. But briefly, 1 is in cabin temp, 2 is outside temp, 6 is coolant temp (F), 15 is in cabin selected temp, 21 is Engine RPMs, 22 AC Compressor RPMS, 23 is vehicle speed in kmh. Also, check 50 and 51 because they are related to the poly v belt. Hopefully they should both read zero.

Good luck and I hope we are starting to get somewhere!.

mbdoc · #13 08-07-2001, 05:13 PM

The early C-class had a recall on the sunroof as most of them failed due to poor design on the lifting angles up to chassis # 025776!
The most common reason the center vent closes under acceleration is a failure of the fresh air vacuum diaphram. Try using the EC button & if the center vent stays open you will know that the fresh air diaphram is the cause.

1994C220 · #14 08-07-2001, 07:30 PM

Ok...I didnt delete all of the codes correctly last time, but this time I did, and it seems the only code that Im getting now is the 60.
I checked all of the temperatures from holding down the REST button, and they all seem normal. The A/C will blow cold air all day as long as the engine isnt revved. I sat in the garage(garage door open of course), and left the A/C on for about 15 min, and it ran fine with the car idling. But as soon as I took it out for a drive around the block, the middle vents cut out.
I tried just using EC as David suggested, but the middle vents still cut out.

Oh, and I found the tidbit about the recall of the 94 C220s and the tilt bracket...will the dealer replace that free of charge? Heres my VIN #
WDBHAZZE3RF059251

David C Klasse · #15 08-07-2001, 08:51 PM

Looks like your car had the sunroof recall corrected.
Glad you are narrowing down the problem...

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