Author Topic: Horn wiring in the steering column  (Read 2260 times)

BertD

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Horn wiring in the steering column
« on: September 01, 2023, 00:47:46 »
I have a 250SL. The horn did not work, so I pulled the Nardi wheel, the multi switch and the horn button. I have the black/pink/yellow coming from the harness and it s capped off. I also have brown coming from the harness and it is capped off. The Nardi has a single connector horn. I understand the brown grounds the horn when the button is pressed. I can touch the black/pink/yellow and the horn works. My question is how is it wired from those two capped wires. The ground needs to get to the button somehow, but I can’t find a connect point. Also, where is the black/pink/yellow connected. I saw one photo on this site and it appears they are both attached to the multi switch?

BobH

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Re: Horn wiring in the steering column
« Reply #1 on: September 01, 2023, 15:30:50 »
Hello, this question seems to have been asked on every classic car forum at some stage, with various answers.  There are lots of posts on here, again with various answers, perhaps search Nardi, and see what it throws up

I do know that you need the correct hub for your car, so assuming you have, all i know is that the ground (brown) wire connects to the black/yellow/rose wire, through the horn push connections.  If you only have one connector on the horn, perhaps the ground is already connected on one side of the horn contact, through the hub somehow, but i'm only guessing

If so all you need to do is solder a spade connector onto the black/yellow/rose wire and connect that to the horn and then try the horn push, perhaps the separate ground wire isn't required on the single connection Nardi horn push.  You said the horns do work, so the +ve supply to the horns is good, there is no +ve at the horn push, you're just switching a ground through the push, so you can't do any harm trying

Hopefully someone who has already managed to get their horn working will comment
February 1965 230SL Automatic
UK delivered RHD
Papyrus white, blue hard top & hub caps
Blue soft top
Blue leather

BertD

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Re: Horn wiring in the steering column
« Reply #2 on: September 01, 2023, 16:47:52 »
Thank you for your response. I have searched this site and the entire internet to no avail.  I believe the hub is incorrect since the copper connecter (ring) that should ground the circuit when the horn is pushed in no way contacts the steering column or anything else.  I think I could probably make it work by running the positive to the horn button, but I don't believe this is the correct way to actually do it.  I also would need to come up with a way for the rotating hub to connect to that positive wire.  As I said, they are not able to make contact as it stands.  Thanks.

BobH

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Re: Horn wiring in the steering column
« Reply #3 on: September 01, 2023, 18:35:24 »
Perhaps speak direct to Nardi, or this company that gets a mention in one of the posts as being knowledgeable  and helpful

http://www.classicowheels.com/
February 1965 230SL Automatic
UK delivered RHD
Papyrus white, blue hard top & hub caps
Blue soft top
Blue leather

rwmastel

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Re: Horn wiring in the steering column
« Reply #4 on: September 03, 2023, 02:27:46 »
With all the other changes mid-way through 250 production, did the steering hub change?  I'd post enough pics here so a knowledgeable person can tell you if you have compatible parts.
Rodd

Did you search the forum before asking?
2017 C43 AMG
2006 Wrangler Rubicon
1966 230SL auto "Italian"