Steering Column/Earth for Horn

[Kruger]

I replaced the steering column in my nova with a GTE column and steering wheel, because I couldnt get the steering wheel off, but now the earth for the horn has been lost, at the moment I've attached a wire from the bottom of the column to the pedal box to create an earth, but I want to know why it isn't earthing as normal, I'm positive all the bolts have been done up, and its just a small niggle I want to sort out,

Thanks