Horn ground wire location | The Z Club of Great Britain

Horn ground wire location

Discussion in 'S30 (240Z,260Z,280Z) Electrical' started by big rex 2, Jun 17, 2015.

  1. big rex 2

    big rex 2 New Forum User

    Hi guys ,

    Can anyone tell me where the steering column grounds to the body?
    I have tracked my horn problem down to a bad ground wire.

    After much head scratching I found both my horns were rusted solid and the relay was wired up in the wrong order. This is the final hurdle ......

  2. moggy240


    if the steering column ground is bad would that not effect other things .try a better earth at the horns first.
  3. Rob Gaskin

    Rob Gaskin Membership Secretary

    When I had a bad steering column ground it affected my horn ( :eek:) and my flashing power :)eek:).
  4. big rex 2

    big rex 2 New Forum User

    Everything is now spot on apart from the horn switch , I ran an earth from the dash bracket and it works perfectly when touched against the copper/ brass brush on the back of the wheel so it had to be a bad ground at the column surely ?

    I know what you mean ,Rob I was thinking other items wouldn't be working but they are all fine and dandy.

    Loosing the will to live here , this is the only thing standing between me and an mot . I even got tempted to wire in a switch but I really really don't want to do .
  5. smileyinside


    Ok Heath Robinson fix - undoubtedly you've considered this already- how about wiring up an earth to the brass brush as a temp fix for mot and taking your time with it later?
  6. big rex 2

    big rex 2 New Forum User

    I'm tempted to that but I really don't want to do a Heath Robinson , I want my new nardi wheel centre to work :) .

    It may come to this though just to get the ticket .

    Rob how did you fix your bad ground ?
  7. jonbills

    Z Club Member

    If adding an earth to the brass bit solves the problem, surely all you need to do is follow the existing wire from the brass bit and check for continuity along it and earth where it ends? or am I misunderstanding?
    Or indeed as Ali says: if adding a 2nd earth wire resolves it, why worry? it'll be invisible inside the cowl /dash and is hardly a significant loss of originality in any case.
  8. Rob Gaskin

    Rob Gaskin Membership Secretary

    I think I just 'ground' the column with a wire - it was about 10 years ago. I know that you would expect the column to be 'ground' already but it worked for me.
  9. Mr.F


    Horn "ground" is at the bracket of the horn itself and live supply is from horn relay. Column horn push switch grounds the live supply to the horn relay.
  10. morbias

    morbias New Forum User

    Maybe it's something to do with the hub adapter you're using?
  11. big rex 2

    big rex 2 New Forum User

    So for me to test this , if I extend the wire for the push switch and touch it on the brass "brush" would the horn sound ?

    cheers guys your help is appreciated.
  12. big rex 2

    big rex 2 New Forum User

    By "testing this" I mean testing the ground of the column.
  13. Paul Henley

    Paul Henley
    Z Club Member

    Horn Issue

    Hi All
    Jumping on the back of this thread as I searched as it's exactly my problem and is driving me nuts. Everything works and is correct, the horns, the relay and all associated wiring. I have 12v to the centre of the horn (the black ring crimp that screws into the horn switch (via the brass arm that is fed from the relay, see pic) As I said everything works including the horn switch but the centre of the steering shaft is not earthed, therefore the relay doesn't switch 12v to the horns. If I short the 12v at the horn switch everything works hence the comment that everything works. So how is the Steering Shaft earthed? Am I not seeing the wood for the trees? :(

    Attached Files:

  14. candy red

    candy red
    Z Club Member

    Run a ground earth wire to the steering column see if the horn works then ,you would expect the column to be earthed where its bolted but maybe the paint on the car is stopping proper earthing .Good luck .

    Derrick :)
  15. Paul Henley

    Paul Henley
    Z Club Member

    Hi, Derrick, yeah that's what I did last night, ran a wire from the black ground wire that feeds into the combination and wiper switches on the steering column and into one of the bolts that clamps the steering column hub together. Everything works as it should and defeats the problem but would be nice to have it "as it should be". I'm with you on the paint theory, I don't recall a specific ground on the steering when I took it apart so I'm guessing the paint is insulating the column from the bulkhead..
    Thanks for your reply,

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