Roof won't work trunk open malfunction

6610 Views 23 Replies 5 Participants Last post by efair, Feb 1, 2016

hawkgt

Discussion Starter · Jan 30, 2016

I have a '08 280 and being in the Midwest, I haven't opened my top in a few months. I tried to do it the other day but the trunk lid open warning symbol comes up on the dash and nothing works. The trunk partition is closed and that switch works fine. I had this problem once before a couple years ago but had it repaired under warranty so I'm not sure exactly what they did. I remember them saying that a switch went bad.
Anybody else experience this? If so, is it something I can fix myself if I buy the switch or is this something best left to the pros?
Thanks,
Jae

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jbanks15

· #2 · Jan 30, 2016

Hi Jae
many threads say the roof should be open/closed often even when not used
was the car on a battery charger/trickle while it was not being used?
the slk must have a great battery and not a good battery, so how old is the battery and has it been tested?
the cold weather might have congealed the lubricants for the latches or even frozen the hydraulic fluid to a degree
you could open your roof manually and see if it unlatches

others will chime in or search

https://www.google.com/webhp?source...TF-8#q=site:slkworld.com r171 roof won't open

http://www.slkworld.com/slk-r171-class-diy/205097-r171-vario-roof-troubleshooting-tree.html

hawkgt

Discussion Starter · #3 · Jan 30, 2016

Thanks jbanks, the battery is new. Replaced last month and even though it's cold, the cars been driven regularly so I don't think it's a battery issue. The top doesn't even attempt to move. No pump whine or anything. I think it is the sensor but I have no idea where it is for the trunk.

jbanks15

· #4 · Jan 30, 2016

peruse this until someone jumps in

check those links i posted in my other post also

http://www.billsden.org/fileadmin/media/mercedes/slk/docs/train_vario_roof.pdf

you check fuses?

http://www.slkworld.com/slk-r171-class-diy/187817-r171-fuse-relay-locations-pics-descriptions.html

curro101

· #5 · Jan 30, 2016

you might want to check out this thread :

http://www.slkworld.com/slk-r171-ge...80-trunk-not-closed-problem-trunk-closed.html

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hawkgt

Discussion Starter · #6 · Jan 30, 2016

Just found the same link. It's the same problem I have so I'll be checking the wires tonight.

jbanks15

· #7 · Jan 30, 2016

do it in the daytime. better visibility!

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hawkgt

Discussion Starter · #8 · Jan 30, 2016

I'll take a quick look tonight and if I do find some cut wires I'll fix it in the morning. Although it's cold so might end up waiting till the spring as long as I know what the problem is.

jbanks15

· #9 · Jan 30, 2016

that wiring loom has a 'bunch' of wires so get out the magnifying glass!

hawkgt

Discussion Starter · #10 · Jan 31, 2016

I checked the wires last and sure enough one of the wires were cut. It was one of the same wires that were repaired by the dealer previously. It's the blue wire which appears to be the thinnest wire. I can see they attempted repair on at least 3 wires in the same area. This must be a bad area because the wire gets kinked 90 degrees as it enters the trunk lid on its way to the control unit. 2 of the thicker gauge wires also had the rubber coating split and exposing the metal wire. I'm going to repair what it visible and shrink wrap the cut wire after the repair. Your right jbanks, there are a lot of thin wires there and a little difficult to work on.

Reactions: 2

jbanks15

· #11 · Jan 31, 2016

Hopefully you found the culprit(s)

curro101

· #12 · Jan 31, 2016

Sounds like you're on the right track !

hawkgt

Discussion Starter · #13 · Jan 31, 2016

Is there anything I can do to prevent this in the near future? Seems like a repair that only lasts less than 2 years is not the kind of thing that that we should expect. I'm thinking the only way to solve this is to completely replace this section of wires. I think the rubber is dry rotting and the bend is causing the rubber to fail.

jbanks15

· #14 · Jan 31, 2016

as long as you cover it good and makes sure that it has 'flex' in that area, it will be good.Mine was fixed (without looking it up) I think over 4 years ago and no issues since.

efair

· #15 · Jan 31, 2016

If you'll post a photo of the problem area I'll do the same - maybe the routing of the wires head something to do with it? Also, I bet there are better and worse kinds of wire to use here.

hawkgt

Discussion Starter · #16 · Jan 31, 2016

2

Auto part Tire Automotive exterior Vehicle Wire

You can see the blue wire thats been cut. 3 other wires were repaired.

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hawkgt

Discussion Starter · #17 · Jan 31, 2016

2

Auto part Automotive design Wire Vehicle Electrical wiring

Side view of the area. The wire loom was already cut by the dealer. He had re -wrapped it with a rough electrical tape. I didn't realize it was part of the repair because there were other areas with the same tape and looked factory.

Automotive design Auto part Automotive exterior Metal Vehicle

All fixed up and put back. The wires enter the plastic guard, but the top takes a severe bend between the plastic guard and the entrance through the trunk lid. I believe it's the top of the plastic guard that is pinching and cutting the thin wires when the trunk is closed. I tried to look inside as the lid was closing and it does roll along the top of the guard. I applied extra tape so hopefully it gets somewhat protected.
Anyway, for now this has solved the problem and all is well for now.
Thanks for all your help!

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etyu

· #18 · Jan 31, 2016

hawkgt said:
View attachment 262233
Side view of the area. The wire loom was already cut by the dealer. He had re -wrapped it with a rough electrical tape. I didn't realize it was part of the repair because there were other areas with the same tape and looked factory.
View attachment 262241
All fixed up and put back. The wires enter the plastic guard, but the top takes a severe bend between the plastic guard and the entrance through the trunk lid. I believe it's the top of the plastic guard that is pinching and cutting the thin wires when the trunk is closed. I tried to look inside as the lid was closing and it does roll along the top of the guard. I applied extra tape so hopefully it gets somewhat protected.
Anyway, for now this has solved the problem and all is well for now.
Thanks for all your help!

IIRC, this area on later models had a C-shaped hard black plastic channel connected to the straight channel to minimize repeated bending stress leading to metal fatigue of the wires and breaking.

I wonder if JBanks et al can find the part number of this C-shaped wire channel reinforcement. Is this found in face-lift R171 models? Can someone check?

I've used some spiral wire wrap of a slightly smaller diameter to reinforce/stiffen the wire loom/harness area a few years back after learning of intermittent 3rd brake light and license plate lamp dysfunction. See photo below:

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etyu

· #19 · Feb 1, 2016

I've now added spiral wire wrap to the wire loom/harness located near top edge of photo, as wire loom/harness enters the opening (with surrounding rubber grommet) at underside of the trunk/boot lid. See photo below:

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etyu

· #20 · Feb 1, 2016

Looks like there's another area where wire loom/harness takes a sharp bend at the lower end of the straight C-shaped hard plastic channel (however, on inspection while opening and closing the trunk/boot lid) it doesn't seem to move significantly.

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