Lol
Yeah u need to earth it if u fit a cmax steering wheel. As I found out after putting it back together because without the earth horn works without ignition switch on. Turn on ignition... No horn.
Earth the brown wire to steering wheel and then horn works as it should.
Also just to let people know that if u have cruise control then cmax with cruise control works in transit.
Cheers for ur help rumble. To me ur almost worth ur weight in bronze