Strange sunroof behavior in 560SEL

I'm the new caretaker of an '88 560 SEL, my first MB. It has 200K miles and is in good shape but has the following problem:

The sunroof does not work as it should. The four-position switch acts as follows: If I press switch at rear OR slide switch backward, the sunroof opens. If I pull switch at rear OR slide it forward, the sunroof closes.

When it reaches the fully-closed position, it continues and the rear of the sunroof will pop up. If I close it from this venting position, it will drop shut and immediately continue to slide open.

To keep it in the fully closed position I have to let go of the button at just the right time.

Any advice on what is needed to fix this problem?

[akry]

quote:

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The four-position switch acts as follows: If I press switch at rear OR slide switch backward, the sunroof opens. If I pull switch at rear OR slide it forward, the sunroof closes

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No mean to be rude, but unless you made a typo, it sounds right to me.

Do you close the sunroof(slide-open)by press up the button, and press the button forward?? If you press UP, it will keep going and tilt the rear end up. The same goes for closing the sunroof. Use press/pull for open/close tilt open sunroof, and press forward/backward for slide open/close.


Andy Kuo


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http://akry.web.com

Thanks Andy, You're not at all being rude, and I appreciate your response to what appears to be a vague post. It is difficult to find the precise words to describe the operation of the sunroof and why I think it is malfunctional, but here's an example of how it is working.

Let's say the sun roof is fully open. I slide the switch forward (without simultaneously pressing it upward or downward) and the sunroof closes. The instant it reaches the fully closed position, the "Rear Pop-Up Feature" engages. There is not even a delay. I have to let go of sliding the switch at just the right split-second, which I can seldom get on the first try.


Shouldn't the sunroof stop when it is fully closed, requiring me to press the switch (not slide it) to open the "Rear Pop-Up Feature"?

Based on your description of how it should work (and that of the owner's manual), I believe mine is not working how it should and was wondering if anyone has experienced this problem before, or had any suggestions.

Thanks Andy and others.

[alan911]

Have the same problem. Found out that it all has to do with timing. In the trunk on the drivers side is the guts of the sunroof motor and the business end of the 4 way overhead switch thats within the motorhousing. This guy tells the motor what to do and when,how far to travel in any direction and when to stop, depending on what you want the sun roof to do i.e. open, close,pop up or pop down., Now to really confuse you... the sun roof cable can only go forward or backward. but the roof can open or close or pop up or down. This is controled by little contacts in the motor housing and works kind of like the stopping position of windsheild wipers. I've had this all apart. The short solution to the problem is a new sunroof motor, as the one of the 4 sets of contacts in the motor housing is faulty and/or its out of "time" if it doesn't fully close or pop up or down. It's not the switch. Its cheaper to keep doing what you're doing.

[barrie]

My sunroof (124) recently developed the same ailment, so I'm also in the process of researching the fix for this problem.

Diagnosis: Since the motor itself obviously works ok, there shouldn't be any need to replace it. The problem is most likely with the actuator wheel or one of the microswitches in the Motor/Gear unit.

Solutions: I understand there is a repair kit for the 124, 126, and 201 models that replaces these components at a bargain (~$60 Cdn). Can PartShop confirm this? (part no. 001 820 13 07)

Repair does not appear to be a big job either as the MB service bulletin allows 1.3 hrs to R&R the motor/gear unit, including installation of this kit. Apparently this was a warranty item!

All of us with this problem (present and future) would greatly appreciate hearing from those of you who have made the fix; and your experience with the MB repair kit.

[barrie]

I was able to confirm locally that the above part no. and applicable models for the sliding-roof repair kit are correct and available from MB dealers. Price is $48 Cdn (~$32US). Still no word from PartsShop as to whether they sell the kit.

Benzmac/PartsShop -- can you please tell us what is included in this kit, and whether it is a fix for the problem that the three of us have described?

Thanks from all who have (or soon to have) a 'runaway' sunroof!

Thanks for your efforts, barrie.

[Bill Wood]

While I'm at the beach on vacation Lee is checking price and availability on 001 820 13 07. We'll let you know.

Gotta go, I'm getting sand and beer in my laptop.

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Bill Wood - Webmaster
MercedesShop.com, LLC

Any word from PartsShop?

[barrie]

Not a word! ... maybe the laptop got clogged with sand. I was particularly hoping we'd get some info on whether the kit is an intended fix for this problem, and what it includes.

Also, maybe Alan would shed more light on how the actuator wheel/microswitch mechanism works to control the timing. Otherwise, one of us is going to have to take it apart and figure it out for one and all.

This is a relatively common problem, and I'm sure we don't need to replace the whole motor mechanism.

Steve, Benzmac, Jeff, Aaron ... someone must have experience with this?

Barrie

[Bill Wood]

Sorry guys. (still shaking sand out of laptop)
We had no luck sourcing the part listed above.

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Bill Wood - Webmaster
MercedesShop.com, LLC

I took out the sunroof motor and have been examining it.

What I discovered, if it's any help: There are two types of micro controls on the sunroof. The first version up to approx. 03/89 (mine) has three microswitches and three relays. The 2nd version had two microswitches and two relays.

The relays are enclosed in a little box (about 2"x1"x1") that plugs into the sunroof motor assembly. The part number printed on it is 124 821 00 47. It's easy to open it and check the relays, and if the part is too expensive or unavailable, repair would definitely be an option.

The microswitches on the other hand, do not seem to be replaceable on their own. The microswitch housing is riveted to the assembly. Checking that they are functional is straightforward.

Relays and switches on mine checked out. I'm embarrassed to say, but I think my problem was ignorance on the adjustment procedure. Now that I know, I will put it back together and will see.

I found on this site some instruction on adjusting the timing, but until I took everything apart, I didn't understand how the thing really worked. What I think was my problem: I didn't see that the white adjustment wheel needed to be pushed in so that it made contact with the sunroof cable.

Anyway, I'll post again after I reinstall the motor...

[barrie]

For some reason, the mechanism is not activating the ‘Close’ or ‘Down’ position (probably related to the actuator wheel).

Here’s my understanding/figuring to date: 1) the roof has only three terminal positions (Up, Closed or Down, and Back), 2) the motor knows only two directions (forward and backward), 3) the Closed/Down position is actually an intermediate position that must be controlled mechanically (via actuator wheel and microswitch), 4) the (white) adjustment knob simply calibrates the ‘end’ position of the cycle.

What’s happening is that the intermediate (ie fully Closed) position is not being activated and the motor continues to the end of its cycle. If the roof is Up (one end of the cycle), pressing the Down switch will lower the roof and slide it Back (to the other end of the cycle). Conversely, if the roof is Back, pressing Close will slide the roof forward and then lift it Up (same thing in reverse). Electrically, the Close and Down switch positions send the same signal (from the schematic).

We need to find out why the intermediate Close position is not being activated (ie stopping the motor). If the associated relay and switch are ok, then the problem must be on the mechanical side (actuator wheel slipping, broken …?). Before you reinstall the motor, it would be a good idea to test this part of the mechanism.

I have a couple of other jobs to do first (refinish wheels and replace fuel injectors), then I’ll tackle the sliding roof. In the meantime, Good Luck and I look forward to your contribution on this one. So will a lot of others, who don’t yet realize it!

Regards,
Barrie

I just installed my sunroof motor and everything works fine now. I feel stupid, because with a little more knowledge, I wouldn't have had to take it out. But I also feel really good for having resolved my problem. So I be stupid and good...

Your understanding is correct, except for the white adjustment wheel (WAK). It doesn't calibrate the end positions (I think the slipping clutch does this, though I may be wrong on this point). But the major function of the WAK is to calibrate the *intermediate* position, which is the fully closed sunroof (the two end positions being fully open, and vented).

The WAK, in its normal position, is geared to the cable. At certain points in its rotation, it engages the microswitches. My problem (which was IDENTICAL to yours) was solved by proper adjustment. The manual was not very clear on this, at least to me, so it took a while to figure it out.

Here are the steps:

1.) Put sunroof in the pop up (vented) position.

2.) Remove side cover from trunk exposing white adjustment wheel on sunroof motor.

3.) Pull white adjustment wheel out one click. (This requires some force and will probably pop out TWO clicks. The white wheel will not turn in this position, so push it back in one click. The wheel can then turn, and it will almost feel like it is turning freely, i.e., not doing anything.)

4.) Poke a thin long straight "tool" (like a paperclip or something thicker) into the small hole next to the adjustment wheel. It will bottom out on the gear that is turned by the white adjustment wheel. By turning the adjustment wheel (either direction) the underlying gear will rotate until an alignment hole will allow the long straight "tool" to push in straight through.

5.) With these holes lined up, rotate the adjustment wheel so its round notch points to the alignment hole.

6.) Push the adjustment wheel back in. This requires some force.

Please tell me how it goes. <I>I</I>

[barrie]

Harry,
I finally got around to fixing my sunroof today -- thanks to your experience!

When my roof suddenly decided to go weird a few months ago I tried the adjustment procedure without success. Seems that my adjustment wheel has NO clicks between being In and Out, so while it rotated across the intermediate position the underlying gear was not rotating (to expose the hole). Getting confidence from your experience, I persevered with the wheel, and while it slipped most of the time I was able to finally line-up with the hole. Now it works but I wonder for how long?

Since it appears that part of the mechanism is badly worn it's likely that I will need to pull the unit before too long. In anticipation, I would much appreciate any info on your method to remove the motor and any tips on the procedure. The MB manual describes 2 methods; the first is to run-out the cable into the passenger compartment, while the back-up method disconnects the cable at the motor.

Again thanks for the exchange and your time. I hope others will find this thread useful when they encounter similar problems!

Regards,
Barrie