Author Topic: Sliding Roof Issue / Sunroof Issue  (Read 195 times)

sethkestenbaum

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Sliding Roof Issue / Sunroof Issue
« on: 18 August 2020, 03:32 PM »
I am having sliding roof issues on my 1980 w116 and can use some help in troubleshooting. The Sliding Roof only occasionally will work and I am resorting to manually opening/closing it using the special tool. When the system works, the sliding roof will typically give me one full open or close and then stop working. Even when it is not working, I seem to ALWAYS have power that correctly flows from the battery through the fuse through to the Sliding Roof Switch (above the Climate Controls) and all the way down to blue and green wires to the junction in the trunk where it plugs into the Sliding Roof Motor. The Sliding Roof Motor itself, if tested by plugging a multi-meter into both inputs, has continuity if tested on its own.

Any advice or suggestions as to what is causing the problem would be helpful. My curent questions are:

1)   How do you remove the Sliding Rood Motor from its place tucked away on the driver side of the trunk?
2)   Is there any type of regulator that is within the sliding roof system that might be tripping? (I don’t believe that there is, but you never know)
3)     Could this be an issue with the air conditioning system?  (I see that the fuse for the roof is shared with the auxiliary fan and my whole HVAC system was recently worked on by a local mechanic.  I don't think this is an issue as I am getting power to the Sliding Roof Motor)
4)     What else should I be checking?

Thanks,
Seth
Seth Kestenbaum
oldcarroadtrip.com
1929 Model A Ford Phaeton
1969 VW Bug Convertible
1980 300 SD Turbo Diesel getting fixed up
1980 300 SD Turbo Diesel rusty parts donor car

daantjie

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Re: Sliding Roof Issue / Sunroof Issue
« Reply #1 on: 18 August 2020, 04:27 PM »
Do a search on the forum, there are tons of posts on this topic, as well there is the Library section as well.
Daniel
1977 450 SEL 6.9 - Astralsilber

sethkestenbaum

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Re: Sliding Roof Issue / Sunroof Issue
« Reply #2 on: 19 August 2020, 01:56 PM »
Dan, The library doesn't always provide the best explanations. Before posting I did sort through older forum posts in trying to track down issues but have not had success. There was a post from 2008 (https://forum.w116.org/mechanicals/sunroof-electrical-puzzle/msg51000/#msg51000) that was helpful but I have not yet been able to figure out the problem or how to get the  motor out of the trunk.There was also another post from 2010 that seemed to indicate that I would have to remove the sunroof panel before I could remove the motor. It also discusses detaching the metal tubes from the motor but didn't say how this is done.... hence my post asking for help.

I am actually hoping there is a resolve that doesn't involve removing the motor.

« Last Edit: 19 August 2020, 02:19 PM by sethkestenbaum »
Seth Kestenbaum
oldcarroadtrip.com
1929 Model A Ford Phaeton
1969 VW Bug Convertible
1980 300 SD Turbo Diesel getting fixed up
1980 300 SD Turbo Diesel rusty parts donor car

rumb

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Re: Sliding Roof Issue / Sunroof Issue
« Reply #3 on: 19 August 2020, 05:37 PM »
from hazy memory if you unbolt the motor assy you also have to disconnect the fore and aft tubes which are held on by a clamp and bolt of sort.   Might have to take motor cover off.

take off the interior headliner panel - open roof half way and unclip at the front and then pull the headliner up through the opening.

 The shaft is easy enough to remove. You may have to run motor to get shaft past motor gears. First unclip the shaft at the front edge of the roof assy. If you disconnected in the rear you can just pull the shaft out.   It's a good idea to do this anyway and lubricate it.

* these are fuzzy directions but once you get in it will be obvious.
'68 250S, '77 6.9 euro, '91 300SE, '98 SL500 '14 CLS550

sethkestenbaum

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Re: Sliding Roof Issue / Sunroof Issue
« Reply #4 on: 24 August 2020, 12:45 PM »
Thanks Rumb.... I also noted in the library that "the drive motor is provided with a thermo switch as an overload protection" (77-190 Trouble Diagnosis, Electrical Sliding Roof".  Because power seems to be getting to the contact that goes to the motor and because the motor occasionally works (after not being used for a while), I am thinking that the overload switch might be getting triggered or is malfunctioning.  Once things cool off here in NY, I'll check it out and post an update.
Seth Kestenbaum
oldcarroadtrip.com
1929 Model A Ford Phaeton
1969 VW Bug Convertible
1980 300 SD Turbo Diesel getting fixed up
1980 300 SD Turbo Diesel rusty parts donor car

sethkestenbaum

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Re: Sliding Roof Issue / Sunroof Issue
« Reply #5 on: 31 August 2020, 10:02 AM »
PROBLEM FOUND AND FIXED!

So there is no confusion about it, you CAN remove the motor from the sliding roof WITHOUT removing the whole assembly. You just need to contort yourself enough to get to the bolts.  This is what I did. With the motor out, I tested the motor against the battery directly.... it sometimes worked.  On the times it didn’t work, if I turned the shaft a little then it would work. I decided that instead of taking the motor apart, I would first see if a window motor could be swapped out (I happen to have had one on my workbench).  Unfortunately, while most of the motor is the same, the shaft is different (longer) in the window motor and has a different top. I wasted a fair amount of time figuring this out. Without a replacement sliding roof motor or desire to spend money on buying one, I decided to take a chance and take apart the roof motor I have. I figured that it was already broken and that I would end up bringing it to an electric motor repair shop if I couldn’t figure it out myself.

How do you take apart the sliding roof motor?  Here is how I did it......

The plastic piece at the end of the wires (where it plugs into the car) can be easily opened with a small flathead screwdriver. Once this is no longer holding the two pins in place, you can slide the wires out of the rubber tube. When the two wires are no longer in the tube, you can just slide the rubber motor cover off the motor. With the cover off, I decided to look for signs of burnt wires or things like that. I didn’t see any problems that were obvious.  I then (again) checked continuity with a multimeter---- assuming that this would show me if I had any “dead spots” on the armature/commutator.  Depending on where I had the things rotated, the continuity would occasionally drop. To address this, I decided to clean the commutator and removed it (which is easy to do) from the motor. You just need to unscrew the two flat heads that hold the top plate (which is the bearing). The armature pops out readily. I know I am not doing a great job describing this, but it will be fairly obvious if you try to do this yourself.   To clean the commutator, just use something gently abrasive. I used a green scrubby sponge from the kitchen.   When the armature was out, I noted that the spring loaded bushes didn’t move.  If they moved correctly, then when I remove the armature the brushes should have effectively popped out of the holders where they sit. Using a small dowel, I nudged them.  They did not budge.  I finally force them out by first PUSHING them further into their tracks and then pulling them out by their wire. To enable these brushes to move correctly, I just used a file and gently sanded them down a little on all sides.  They now were able to fit back in their housings and moved freely.  Keep in mind, they are spring loaded --- so there is some delicate work here as you need to get the spring back into the housing then the brush.  The fun part is getting the armature back into place while keeping the spring loaded brushes in their track. I did it with some finagling including using toothpicks and string. I’m sure someone else has a great trick on how to do it more easily.  Regardless, I was able to get the armature back in place, the brushes set up right, the top metal plate back on the housing, the cover on, the two wires back through the tubes and the two pins set back in the housing.  With this all together, I tested the motor directly with the battery and it worked every time.

The sliding roof motor is now back in the car and NOW CONSISTENTLY WORKS. If I was to do it again, it would probably take me about 2 hours in total.  I probably should have taken some photos or videos.
« Last Edit: 31 August 2020, 02:46 PM by sethkestenbaum »
Seth Kestenbaum
oldcarroadtrip.com
1929 Model A Ford Phaeton
1969 VW Bug Convertible
1980 300 SD Turbo Diesel getting fixed up
1980 300 SD Turbo Diesel rusty parts donor car

rumb

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Re: Sliding Roof Issue / Sunroof Issue
« Reply #6 on: 31 August 2020, 11:37 AM »
Great news. The brushes in motors often get stuck.
'68 250S, '77 6.9 euro, '91 300SE, '98 SL500 '14 CLS550