Chimera horn slip ring

[Andrew P]

Recently the horn on my 93 Chimera stopped working so I had a look at the slip ring and connections behind the steering wheel. I found the reason was the connection to the spring loaded pin that pushes against the slip ring had come off. That fixed the horn but I noticed that the pin grates against the slip ring when I turn the wheel and I wondered if it should have a carbon brush on the end, like in an electric motor. Mine looks like it has a raised edge and there is a fair amount of metallic dust so I'm wondering if something has gone missing.

Anybody any ideas?.