Horn problems (suspected steering column earth problem)

Hi, I am having problems with getting my horn to work on my 1983 golf mk1.

The horn definitely works when given a permanent live and ground to a strut bolt. I have traced it to being a fault with the earth. When i connect a multimeter between the + and - wires going to the horn, it reads 5v but when you connect the earth to the strut top of battery -ve it reads 12v. I have traced it back to where the steering column earths as i bipassed the steering wheel with a wire going from the junction on the steering column straight on to the splined part where the steering wheel goes on the column. Still 5v.

So my question is, where does the steering column earth to and why would it be reading 5v; rusty connection somewhere? Any help much appreciated

It is the rack itself that has an earth wire screwed into it, right on the bulge in the middle of the rack, visible from the top of the car.

lhasadreams said

It is the rack itself that has an earth wire screwed into it, right on the bulge in the middle of the rack, visible from the top of the car.

Thanks, ok so now i have narrowed it down to somewhere between  where the column meets the rack and where the earth wire comes out the rack. but its just started raining so i will have to wait for the shower to pass

No worries, you can just see it in this picture of mine from its 2004 rebuild:



Just to the right of the left hand rack mount is a threaded pillar with a nut on it, make sure a wire is run to it from an earth point, I think mine ran from one of the coil clamp mount bolts.
That is a replacement rack, I think the originals had a cross head screw to hold the wire on the rack.

All sorted, thanks for your help