Steering column ground?

[mopowers]

What is the original purpose of the short steering column ground wire? Is it for the horn? Shouldn't the column support mount do the same thing and act as a ground? The wire seems redundant.

Thanks!

 

[ab7fh]

Yes it's for the horn.

My thought is that the columns are painted before assembly and will not provide a good ground through the painted female threads. They certainly wouldn't take the time to clean the threads on the production line.

 

[mopowers]

That makes sense and is about what I was thinking. Pretty interesting... Thanks.

 

[moe7404]

in 1984 i bought a new fury pl. and of course bought the factory service manual. in about 4 mo the horn stopped working. so in the manual the horn section. the VERY first paragraph said that if the horn stops working. put it in park and turn the key to run. some combination of lights means that the steering column is not grounded. so why do they put the info in the very first paragraph?

 

[keith sims]

I'm having signal light on my 73 Duster put new Signal light switch don't work

 

[RedFish]

so once upon a time, before collapsible columns, the 3 little nylon sliding clips in the column support were cast metal. The column ( shift indicator lamp and horn ) had no ground issues so a jumper wasn't req'd. The column might ground through the shaft, its bearings, the box coupling grease whatever but that ground path might come and go too. Anyway... When those little clips changed to plastic/nylon the ground jumper was added. Then key dingers and switch lighting came along to use the same chassis ground.
For what its worth, Fords had what was commonly called a rag joint where we have a box coupling. That rag joint had a ground jumper over it too. Without it in place their steering wheel mounted cruise control switches wouldn't work.