Hey all,
I recently picked up a '98 M3 in pretty good shape as a project car for my dad and me. One of the things that need fixing is the horn, it doesn't sound when you push on the steering wheel. We tested the relays, took apart the steering column, and ran some power through the horn connector to initially test things. The horn sounds fine when power is run through the connector but when we took the steering wheel off the column the horn connector wasn't connected to anything. The grounding ring was also hanging loose. Pictures attached.
We read a bunch of guides but can't seem to figure out how this thing is supposed to be wired (and yes we looked at the relevant parts of the Bentley Manual); the 4 spoke steering wheel only seems to have the airbag connector, nothing for the horn. One option I'm considering is buying a 3 spoke wheel I saw on Craigslist that has both horn and airbag connectors, but I'd like to make this work if possible.
Thanks!
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Not sure why it uploaded horizontal! Also the car is a Boston Green/Modena sedan, the last 7 of the VIN is EE12973
This thread has information about how to swap from the 4 spoke steering wheel to the 3 spoke. It includes relevant information about the horn wire in post #8. The 4 spoke wheel uses the metal ring at the base of the steering wheel to complete the horn circuit.
http://www.m3forum.net/m3forum/showthread.php?t=33048
You'll see that on the 4-spoke wheel, theres no horn contact switch. I don't have a pic of that so I'll have to explain it. On the bottom of the switch bracket, theres a small white round thing, with a metal peice sticking out of it. Thats your horn contact switch. For the time being, disconnect that from its connecter underneath the coloumn. (The location of where the horn contact switch will be is marked by the yellow arrow)
You can see the horn contact switch in this picture. My guess is that if you don't have this, your car once had a 3 spoke steering wheel installed. When installing a 3 spoke wheel, you cut the connector off the switch and wire it to the horn wire from the 3 spoke slip ring.
1998 Titanium/Dove M3/4/5
2020 Toyota 4Runner
I noticed that all the guides were 4 spoke to 3 spoke conversions, they never had what stock 4 spoke wiring is supposed to look like.
So, that makes sense to me; this car (3.2L sedan) originally had a 4 spoke, a previous owner swapped in a 3 spoke and re-did the wiring, and then the owner immediately prior to me swapped the 4 spoke back in but just didn't really care about having a horn. I looked up the carbon pin to order it but it doesn't seem to have originally come on the Sedan (https://www.amazon.com/BMW-Genuine-S.../dp/B01JEG2JY0, found by searching part #32311158475)...
I'm going to order this pin anyway to fix this but, at this point, I'm wondering wtf the wiring is *supposed* to look like on this version of this car
Hmm, not sure why it says that. On real OEM, I believe it's part #7 in this diagram, but it isn't listed in the parts list.
http://www.realoem.com/bmw/enUS/show...diagId=32_2427
My car (also a '98 sedan) did have that pin. In fact, it might still be sitting on my workbench from my install. I'll see if I can find it when I get home tonight and snap a pic, just to confirm.
1998 Titanium/Dove M3/4/5
2020 Toyota 4Runner
Here are the stock parts from my 98 sedan that I removed when I did my 3 spoke swap.
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1998 Titanium/Dove M3/4/5
2020 Toyota 4Runner
Awesome. This great to see, thank you! I've ordered the pin from ECS Tuning. It should be here next week, I'll post up here when I get it working.
Ok, something else I just noticed. It looks like you also have the switch bracket for the 3 spoke wheel installed. Notice on mine, on the upper right part, there is a little circle. This holds the slip ring pin. I think all it does is keep the slip ring from spinning around the column shaft. On the 4 spoke switch bracket it's on the right, but on the 3 spoke bracket it's on the left. Notice yours is on the left.
Last edited by RightYouAreKen; 05-09-2017 at 02:44 PM.
1998 Titanium/Dove M3/4/5
2020 Toyota 4Runner
Hey guys I recently changed the steering wheel on my 95 328 from the 4 spoke with slip ring to the 3 spoke steering wheel. The 3 spoke wheel has an extra connector (I don't know what it's for?) And i busted off the horn contact accidently not realising the 3 spoke wheel is completely different. Can someone please explain how I connect the horn to the 3 spoke wheel? I can't seem to understand other writeups on how to do it. If anyone has pics it would be really great.
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Hi can you please explain how you connected the horn to the 3 spoke wheel? I've just changed from the 4 spoke with slip ring to the 3 spoke. I just need to know which wire on the steering wheel connects to the horn wire
Last edited by oliverd642; 06-20-2017 at 03:20 AM.
The DIY I posted above has the information you need. See posts #11, 12, and 13.
http://www.m3forum.net/m3forum/showt...t=33048&page=2
1998 Titanium/Dove M3/4/5
2020 Toyota 4Runner
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