Power Trunk Closing Issue
11-01-2023, 11:22 AM
#1
Junior Member
Thread Starter
Join Date: Jun 2021
Location: Southern Mississippi
Posts: 26
Likes: 0
Received 19 Likes
on
10 Posts
1984 W126 300SD & 2013 W221 S550
Power Trunk Closing Issue
Hello All,
I experienced an interesting issue the AM, during our first major temperature drop of the year. I walked out to the car, popped the trunk via key fob, and it power opened with no issue. Once I loaded my cargo, I noticed that none of the trunk lights, or back facing indicator lights were lit. Thinking it was a nonissue I pressed the truck close button and the trunk stayed in the upright position. I started the car, thinking it might be a weak battery, and pressed the button again with no luck. Channeling my inner diagnostic technician, I manually triggered the latch closed with a key, while the lid was open, then pulled the outside trunk open switch. The latch sprung open and all the lights turned on, and the automatic closing trunk functioned fine. Post commute to work, the same interesting issue reappeared, and was solved via the previous method described.
Anyone else experience this issue before? My mind defaults to sticky or sluggish microswitches within the latch mechanism. Is there a spray cleaner which could be utilized to resolve this issue and save myself the need to replace the entire mechanism and loosing $430?
P.S. I have a Mercedes XENTRY Diagnostic Scanner, but the multiplexer (vehicle to computer interface) is currently with a friend, so I can't pull codes.
I experienced an interesting issue the AM, during our first major temperature drop of the year. I walked out to the car, popped the trunk via key fob, and it power opened with no issue. Once I loaded my cargo, I noticed that none of the trunk lights, or back facing indicator lights were lit. Thinking it was a nonissue I pressed the truck close button and the trunk stayed in the upright position. I started the car, thinking it might be a weak battery, and pressed the button again with no luck. Channeling my inner diagnostic technician, I manually triggered the latch closed with a key, while the lid was open, then pulled the outside trunk open switch. The latch sprung open and all the lights turned on, and the automatic closing trunk functioned fine. Post commute to work, the same interesting issue reappeared, and was solved via the previous method described.
Anyone else experience this issue before? My mind defaults to sticky or sluggish microswitches within the latch mechanism. Is there a spray cleaner which could be utilized to resolve this issue and save myself the need to replace the entire mechanism and loosing $430?
P.S. I have a Mercedes XENTRY Diagnostic Scanner, but the multiplexer (vehicle to computer interface) is currently with a friend, so I can't pull codes.
11-01-2023, 04:09 PM
#2
I would expect its snapped a wire and whilst your manual intervention magically woke it up twice, it was probably wiggling the lid that luckily got the just snapped wire to make a bad connection....
the ones I've read about and exactly like the one I worked on (although not an S class).... you find they route the wires to ensure the loom has a deliberate path making most of the lid opening movement around the hinge land at one stress razor, then cable tie it into submission very tightly, having calculated the ave number of openings over x years until it snaps the larger brown earth wire like a carrot - nicely outside the warranty period
Next time get a wire strip both ends and see if you can just make a new earth to see if the lights come on... (US seem to call earth - ground)
.
the ones I've read about and exactly like the one I worked on (although not an S class).... you find they route the wires to ensure the loom has a deliberate path making most of the lid opening movement around the hinge land at one stress razor, then cable tie it into submission very tightly, having calculated the ave number of openings over x years until it snaps the larger brown earth wire like a carrot - nicely outside the warranty period
Next time get a wire strip both ends and see if you can just make a new earth to see if the lights come on... (US seem to call earth - ground)
.
Last edited by BOTUS; 11-01-2023 at 04:12 PM.
11-01-2023, 04:12 PM
#3
There was a nice video somewhere about how to find and repair those broken wires at the trunk hinge. I followed it a year or two ago and discovered that I didn't have any broken wires.
11-01-2023, 04:15 PM
#4
we had one the other day, he found it inside the lid behind the trim in a bit where there is no movement of the loom - the S class electrics are a bit more special than a normal car
