Pagoda SL Group
W113 Pagoda SL Group => Electrical and Instruments => Topic started by: RPSchuetz on November 08, 2019, 15:00:19
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Greetings all!
My horn is acting up. As I turn the steering wheel to the left, when the 12:00 position gets to about 10:00, the horn sounds until the the 12:00 position gets past the 9:00 position, then it stops again. I’ve removed the steering wheel and nothing appears out of the ordinary- no frayed or exposed wiring, etc. Anyone have any prior experience or thoughts about this particular issue?
Much thanks
Reinhold
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I had a similar problem and it was the wire stripped at the base not the top of the steering shaft.
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Thanks - I’ll check!
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As a follow up, is that something you accessed from the interior under the dash, or from under the car once on a lift?
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WOW!!!! I loged on to the forum tonight to see if anyone was or has had a problem like this. My issue is that my horn begins to sound for what I thought was no reason while driving.
Thanks for the input, I am going out to the garage right now to check it out.
Thanks Mark
1967, 1968 250sl
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Mine has an odd connection somewhere
If I touch a metal object to the horn ring, the horn sounds ::)
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Hi Garry,
is the wiring loom accessed from inside the car in the footwell or under the bonnet? My horn wont shut off since doing a right hand turn so I suspect I have the same issue.
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I took the fuse out and then gave it to the Auto electrician to sort out as I believe you need to access the bottom of the steering shaft from under the car and I didnt have a hoist to get under at that point.
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While there could be a chaffed wire somewhere, the issue at hand is most likely a bad or worn contact ring and/or a bad or worn contact switch. Pictures of each are below. These are wear items and will cause the problems both of you are experiencing. I'd definitely suspect these parts before I would any wiring. It must be understood that every time the steering wheel is turned these parts wear. Granted, it'll take 40-50 years, but they do wear.
The actual wire harness runs through the turn signal switch wire loom. It runs down through the steering column and exits out the side of the steering column just under the dash above your legs. It terminates into a 10 or 16 pin phenolic plug housing which plugs into another 10 or 16 pin phenolic plug housing. Nothing regarding the horn wiring is under the car or behind the dash. The wires running to the horns from inside of the car run through the harness in the engine bay, across the front cross member, and then to the horns themselves.
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Aaron thankyou..that's very helpful.
My car is a 64 230sl manual and have only owned it a short time. I had a 69 280sl auto many years ago. On this car the chrome horn ring on the steering wheel feels a little sloppy to how I remembered it should feel, so maybe theres wear or a dodgy repair in the wheel contacts. I will start with the wheel..thanks!
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Mel, the 230 is a bit different. There are two different contact rings used on the 230 models, but there is no set of contact brushes/carbon piles like the late 250 and 280 models use. Both versions of the 230SL contact rings are adjustable. In the pictures below you can see the three screws on the early version, and the one screw on the later version. If these are too tight or loose this can cause the horns to sound when turning the wheel. If the springs inside of them have weakened or broken that will also cause the horns to sound when turning the wheel.
The loose horn ring....they were supposed to be tensioned by a spring that was compressed between the inner race of the steering wheel shaft bearing and the rear bracket that the horn ring was attached to with the chrome acorn nuts. However, I've seen some later 230 models that didn't have this spring and relied on the spring tensioned contact ring to keep the horn ring taught. I'll have to rely on someone else to comment further on this aspect of things. I just don't remember enough, and I'd hate to mislead you. Regardless, I still think that your issue will have something to do with the contact ring.
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I stand corrected.
As i said i handed it to an auto electrician as i am not comfortable messing with electrics who advised that in my case it was the wiring running down the column. Didn’t realise it came out the side of the column inside the car.
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so far all is working ok. On my car the 2 wires connecting to the sprung contact rings are attached by screws which were a big target for the loose spring to touch and short out.
Im sure the steering wheel has had numerous dodgy repairs done over the years. Im just pleased it's working at the moment..will investigate further in the future
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Turns out my problem was the disintegration of one of the three small rubber nubs inside the center of the steering wheel that separate and insulate the horn ring from the other metal bits. Was lucky to find a set of three in Texas, the Classic Center no longer stocks them...
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Do you know the MB part number?
Thanks Peter
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GOOD NEWS!
This part number is A 115 464 00 24 (3 pieces needed), it is available again!!!
I have 24hrs availability at the dealer. It costs $0.9 per piece.
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Hi Pawel,
Are you saying this part is now available from Mercedes?
Rob
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Hi,
availabilty at MB today.
...WRe
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Thanks - might pick up a few sets with my next order as mine were all hard and the odd one missing.
Cheers
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I cannot find that part A1154640024 anywhere. I did see it in a german site but the price was above 7 Euros and had no picture. Is it Anywhere in the USA?
thanks
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I just checked. It is available at the MB dealers 24hrs. Maybe it needs to be Classic Center in the US?
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About this horn issue, I totally get where you're coming from. Dealing with chaffed wires can be a real pain. But I've got to agree, those contact rings and switches seem like prime suspects. It's crazy to think about how even the smallest parts wear out over time, right? Now, about those train horn guns with remote control... I stumbled upon this site, bosshorn.com (http://"https://bosshorn.com/products/dewalt-train-horn"), and it got me thinking. Imagine the fun of blasting that thing! But, back to the topic at hand, focusing on those contact rings and switches sounds like a solid plan. Let's tackle this issue step by step.