Horn not working

[maltbbe]

Not sure whether this should go in the Mk5 or Mk6 section... but I have a Mk5 GTI with a retrofitted Mk6 GTI steering wheel, adapted with a CH-version SWCM and using the original Mk5 clock spring. Until recently, it was working perfectly - steering wheel controls, steering assist, airbags etc. all functioning as intended - until the horn stopped working a few weeks ago.

I haven't done much investigating, but I can't hear a relay clicking when I depress the horn, so I'm assuming the issue isn't with the horn itself. VCDS scan doesn't show any error codes relating to the steering wheel or SWCM. I've taken off the airbag and fiddled with the connections for the horn on the back (all black wires), which hasn't fixed anything. From what I've read, it's usually a problem with the clock spring or the horn relay - I know the former is a bit of a pain to replace, and wondering if anyone has any other ideas? Or if anyone can help explain how the switch that activates the horn actually works? I got the steering wheel from a wrecked Mk6 and the wiring for the horn on the back of the airbag unit looks a bit janky, so wondering if that could be where the issue lies... any help appreciated

[kamold]

Start with the airbag wiring harness.
You need a revision C.
They can be had for about $30 on eBay.
If that doesn't fix it then yes you will need to look at replacing the clockspring.

[The_Hawk]

Start simple / cheapest. There is a few things you can do for free

Fuse (Fuse you can check visually $0)

Voltage ar the horn itself with a multimeter or a small bulb when you press the button inside (or just power the horn and see if it works) ($0)

Relay you could probably swap for another 449 (heater mirrors) ($0)
Horn Relay - VW GTI Forum / VW Rabbit Forum / VW R32 Forum / VW Golf Forum - Golfmkv.com

Then the airbag wiring harness ($30)

Can you short the pins for the horn in your current harness to see if the problem lies in the wheel itself? (although this will throw a airbag code afterwards you will need to clear).

While it might be common for the harness to go, it doesn't mean it's not something else.

[maltbbe]

Thanks for this! Haven't had time to look at this yet but will go through some of these ideas soon. The fuse is fine - haven't checked the horn itself yet. I'm assuming you need to take off the wheel and clock spring to get to the airbag wiring harness? (I've had to do this three or four times already to sort out issues with my wheel conversion - it's a frustrating job cos all the plastic clips are so hard to reach, plus I can never seem to get the steering wheel straight again...)

[The_Hawk]

Just power the horn directly on the other end, much easier than pulling out the steering wheel While it's unlikely, if the horn is dead you find it easily.