I have a 92 400E that at some point had the leather wheel replaced with a synthetic one. I have a wheel from a 92 W140 that is leather and very nice.
My wheel has the old style "clock spring" contact plate.
Both wheels have the same inner "guts"....same metal horn ring. But the one in the car now, the one I want to replace, has a backing plate that is black with no preformed male connectors which I assume would be for a ground wire.
The present wheel has a brown ground wire ( I assume its a ground) connected to the clock spring in the centre and can be unplugged. It goes all the way around the horn ring (those whiteish metal pieces that look like boomerangs) and is connected to each one of four contacts. Two on each side.
The other black wire in the centre is permanently connected to the clock spring and then goes to a male connector on the horn ring.
So...simple swap. Remove and replace the clock spring into the new wheel...easy.
Connect the black wire in the centre to the same place on the horn ring in the new wheel. This is the wheel that has the metalic yellow coloured backing (or bottom) plate with male conector (upper left) whereas the original has a black backplate with no connectors.
Now..I made a small wire to connect the ground to the clock ring at the centre (place the original brown wire was connected to) and then up through the hole to the left and connect it to the yellowish metal backplate at the provided male connector.
My logic is, that set up will complete the circuit when I use the horn...right...? WRONG!!
Pretty simple I thought.....and it seems basic but whenever I use the horn it blows a fuse....!
Can someone please tell me what I'm missing.
The wiring is the same with the exception being I am connecting the ground (I think it's a ground) to only one spot on the base (back) plate where the original setup had that brown wire connected to each of 4 contacts, on the bottom or the base plate. Can't see it in the picture because it is underneath.
Any one know what's wrong with my logic....and to take a minute to tell me how to connect the horn?

 

Why do you need the VIN?

 

OK.....so I managed to get the wheel installed and put the ground (brown) wire from the slip ring connector to the male pin on the bottom part of the horn ring. No problem. Tested the horn and it worked !!!!....for a couple of toots...only. Then I could hear something clicking when I tried the horn but no horn. Turns out the noise is from the horn(s) themselves. A diaphram I assume. Anyway, no horn...BUT........ if I disconnect one horn (either one) then the other horn will work. So it would seem that when I press the horn thwere is less than 12V going to the horns.....is there a relay somewhere that maybe I blew ?

 

I’m experiencing the same issue on my W463. I replaced the steering wheel (vinyl to leather) and connected the ground. When it start up the vehicle, the fuse pops.

what was the wiring solution please??
I know this is an ancient post, and hope I can get some help

thanks!