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Horn troubles

Posted: 24 Sep 2023, 13:18
by matthew13
Hi all, I have 1983 2ltr Aircooled van. Horn had stopped working so just replaced it and now all I get when I press the horn inn the steering wheel is a ticking and dull knock from the relay. Any ideas what the problem may be? Have checked and have just under 12v at the horn.
many thanks

Re: Horn troubles

Posted: 24 Sep 2023, 14:30
by maxstu
Try it with engine running to boost voltage. Probably a poor earth somewhere. Take horn off and try running it with two appropriate wires directly on your starter battery.
Warning. It may be scarely loud!

Re: Horn troubles

Posted: 24 Sep 2023, 15:07
by Oldiebut goodie
Check the earth at the bottom of the steering column, quite often gets overlooked.

Re: Horn troubles

Posted: 24 Sep 2023, 16:39
by Robsey
The brown wire that attaches at the bottom universal joint. / collapsible joint.

Image

Sorry for the fuzzy old photo...

Re: Horn troubles

Posted: 25 Sep 2023, 08:33
by matthew13
Thanks for the reply's. I have tried the horn whilst I'm driving and it works fine but with the ignition on or just the van idling nothing, apart from the knock and tick from the relay. Would this indicate a bad earth?

Re: Horn troubles

Posted: 25 Sep 2023, 10:15
by matthew13
So I have now checked the earth and cleaned things at the base of the steering column and re crimped tighter the earth that goes to the steering wheel and checked the one that goes into the horn and they're all fine. Also getting slightly more voltage at the horn terminals 11.6v and still not working. Are they're any other deaths I need to check and also I have a spare yellow\black wire connection at the horn, is this normal?

Re: Horn troubles

Posted: 25 Sep 2023, 10:47
by Robsey
If all the supply wires are okay,
And the grounds are okay,

Have you checked and cleaned the horn-push switch contacts and the pick-up ring.
The steering wheel parts are the usual weak spot due to the wheel being almost constantly moved during driving...
I will look up my wiring diagram for the early horn set up.
The mention of a relay is a bit confusticating, as the relay is usually only fitted on dual horn vans.

Looking at a 1983 van wiring, there is no relay.

Wiring should be -
Fuse 12 (8amp) - black yellow direct to horn positive pin.

Horn negative pin - brown wire to a single pin connector (T1d in wire ).

T1d out wire - brown blue to horn-push switch (in wire).

Horn push switch (out wire) - brown to ground via horn ring, then the brown link wire at the base of the steering column.

A very simple circuit.

Re: Horn troubles

Posted: 25 Sep 2023, 12:08
by maxstu
matthew13 wrote: 25 Sep 2023, 08:33 Thanks for the reply's. I have tried the horn whilst I'm driving and it works fine but with the ignition on or just the van idling nothing, apart from the knock and tick from the relay. Would this indicate a bad earth?

Yes and no. Simply could be corrosion, rust or rust prevention coating the horn plate to vibrate until it gets decent voltage.

Re: Horn troubles

Posted: 25 Sep 2023, 16:55
by matthew13
To be honest I was just guessing a the ticking being from a relay because it was coming from behind the fuse box. So I have checked the horn push switch contacts and cleaned the, not sure what the pick up ring is! 
so for wiring, from the fuse box I have a red wire that runs to the positive horn terminal and a brown to the negative and a brown and black to the connections at the horn push. I also have a spare yellow and black wire at the horn which I have no idea where or what it's for. But I thinking always been there.

Re: Horn troubles

Posted: 25 Sep 2023, 16:56
by matthew13
Tried to attach photo but not sure how!!!

Re: Horn troubles

Posted: 25 Sep 2023, 17:09
by R0B
Image

Re: Horn troubles

Posted: 25 Sep 2023, 18:14
by matthew13
Image

Re: Horn troubles

Posted: 25 Sep 2023, 18:51
by Mocki
Right so the red is an added extra and not original….. the yellow/b;lack is the original positive . The horn should be constant live (+12vdc) all the time the key is on with switched neg (-12vdc) there is no relay originally so I suspect some "feck" has taken place previously

Have you tested the horn actually works by applying pos and neg 12v direct from the battery

Re: Horn troubles

Posted: 25 Sep 2023, 19:43
by maxstu
maxstu wrote: 24 Sep 2023, 14:30 Try it with engine running to boost voltage. Probably a poor earth somewhere. Take horn off and try running it with two appropriate wires directly on your starter battery.
Warning. It may be scarely loud!

That's what l recommended, Rob.. :ok

Re: Horn troubles

Posted: 25 Sep 2023, 20:25
by matthew13
Yep I know the horn works because when I'm driving it works just not with ignition on or idlying . I'll try switching the wires across tomorrow in the daylight!