Bongo Fury

Hi guys,
I purchased an aftermarket steering wheel and a separate boss kit compatible with bongos.
I've switched the old one out with the new one no problem, however the horn is not working
Now, the boss kit has one wire coming from it, but the horn has two terminals on the back. From what i understand, one of those terminals needs to be earthed?
Any idea on how to get the horn to work and make my bongo road legal again would be much appreciated.
Thanks in advance,
Adam

Earth the second wire from the switch is all that is necessary is there no suitable screw nearby, assuming that the new boss isn't plastic !

How was fitting the new steering wheel? I'd like to replace mine but not sure how best to go about it.

Are there certain sizes or anything?

This topic might interest you. Info on a couple of different steering wheels. Fitting with/without airbag. https://www.igmaynard.co.uk/bongo/forum ... =3&t=69147