The horn is driving me crazy! (Shorting out, so the horn is always making a noise)

[Pabloako]

Daisy (1972 Lowlight) is getting ready for her roadworthy so I can get her registered and there is one thing that is left to get working, however it is driving me crazy. The horn worked for a while and whilst going on a sneaky test drive (along my driveway obviously) the horn started coming on.  All I could do was disconnect it to shut it up.

I have been playing with the multimeter and there is continuity between the inner pole/column of the steering and the outer tube, which has that silly little tab at the bottom that the ground wire to the horn is attached to.  So, obviously the outer tube is shorting somewhere and becoming grounded, however I cannot find where.  I have put silicone tape at the top where the indicator arm is "compressed" onto the steering column and I have put silicone tape around the bottom of the outer tube, just incase it is shorting out at that end.   When I turn the key, the horn comes on. 


Does anyone have any experience with getting these temperamental things to work, or any work around and different to the way Vee Dub did it all those years ago?

[grumble]

Daisy (1972 Lowlight) is getting ready for her roadworthy so I can get her registered and there is one thing that is left to get working, however it is driving me crazy. The horn worked for a while and whilst going on a sneaky test drive (along my driveway obviously) the horn started coming on.  All I could do was disconnect it to shut it up.

I have been playing with the multimeter and there is continuity between the inner pole/column of the steering and the outer tube, which has that silly little tab at the bottom that the ground wire to the horn is attached to.  So, obviously the outer tube is shorting somewhere and becoming grounded, however I cannot find where.  I have put silicone tape at the top where the indicator arm is "compressed" onto the steering column and I have put silicone tape around the bottom of the outer tube, just incase it is shorting out at that end.   When I turn the key, the horn comes on. 


Does anyone have any experience with getting these temperamental things to work, or any work around and different to the way Vee Dub did it all those years ago?

Hi Pabloako, a suggestion-- pull the steering wheel off and see if the horn still blows- from memory there is an insulating sleeve between the column and the bearing, if this is missing the circuit is complete because the power is constant at the horn and the earth circuit is controlled by the button. try this and work from there.

[Wayne Murray]

There is a plastic insulating sleeve that goes between the outer steering column and the ignition housing, if that is missing or in the wrong place your horn will be doing what you already know, continuously on. 
Also check the wire that comes up the column and make sure it's on the correct side of the steering coupling disc at the bottom of the steering shaft.
Where are you located?

[Pabloako]

There is a plastic insulating sleeve that goes between the outer steering column and the ignition housing, if that is missing or in the wrong place your horn will be doing what you already know, continuously on. 
Also check the wire that comes up the column and make sure it's on the correct side of the steering coupling disc at the bottom of the steering shaft.
Where are you located?

Thanks for your replies Grumble and Wayne.
I will focus at the top tomorrow and do a few tests to see if I can see where the issue is.  I have removed the steering wheel and the column and tube are still 'connected' , so I will lift up the outer tube and support it with plastic and work my way up to see where the issue could be.  My last thing to do before getting someone to do a roadworthy and it has taken me a day of getting nowhere!   My last bit of frustration before the next frustrations can start!

(I have updated my profile, I am up in Ocean View, Qld (up in the hills) and I am very confident my brakes work very well after a couple of small drives up and down my street. )

[Pabloako]

There is a plastic insulating sleeve that goes between the outer steering column and the ignition housing, if that is missing or in the wrong place your horn will be doing what you already know, continuously on. 
Also check the wire that comes up the column and make sure it's on the correct side of the steering coupling disc at the bottom of the steering shaft.
Where are you located?

Fixed it!  The issues was at the top and the plastic sleeve you mentioned. I removed it and wound a load of silicon tape (the stuff you can use to put a temp fix on a water leak). It is all fitting nice and snug and the horn now  only works when I want it to!

There is still about 1.2v between all the time between the outer sleeve and the inner column, however that doesn't seem to be enough to make the horn work until I press the button and then it jumps up to 12.8v.

I class that as a victory!  

[grumble]

Fixed it!  The issues was at the top and the plastic sleeve you mentioned. I removed it and wound a load of silicon tape (the stuff you can use to put a temp fix on a water leak). It is all fitting nice and snug and the horn now  only works when I want it to!

There is still about 1.2v between all the time between the outer sleeve and the inner column, however that doesn't seem to be enough to make the horn work until I press the button and then it jumps up to 12.8v.

I class that as a victory!  

Well done a lot of problems appear to be major but there are usually minor things causing them.

[Oldman]

Well done!
Gotta love an easy fix…..

[Doob]

Great to hear you have fixed it   I am not exactly sure what you taped up or how this tape fixed it?  Could you add some photos please?
Horn issues seem to be a common problem and there were some excellent discussions on the old Kombi Club Forum re this topic - it would be good to build up the knowledge base again

I was in the process of taking photos & drawing up a horn circuit diagram of my 1971 low light Kombi that I thought might be the same, or similar, to your 1972 Bus.  I know later models were very different (after 1974?).  Even though you have fixed the horn, I might just add to this thread, my understanding of how the horn system works on my Kombi and also attach my wiring diagram and photos.

In a nut shell for my Bus - the power to the horn comes from the battery, via the ignition switch (need ignition on to blow the horn) - via fuse #10 - to the horn.  The wire from the fuse to the horn is black with yellow stripes and is bundled with the brake light wiring to the master cylinder.  The brown earth wire, from the horn, goes up through the rubber steering coupling and inner steering column to the steering wheel hub.  Within the steering wheel hub, this earth wire attaches to a sprung & isolated floating ring (for want of a better technical term).  When the horn  button is pushed, this 'floating ring' makes electrical contact with the metal steering wheel hub and steering column.  The steering column outer tube is earthed to the chassis via an electrical wire at the bottom end of the tube (see Bentley Manual Section 2 Fig 9-15.) 

For my 1971 Bus there is continuous electrical continuity between the steering wheel hub, the inner steering column, the outer steering tube and the chassis. This is required for the horn to work. (i.e. trying to isolate the steering column from earth would result in the horn not working when the horn button was pushed).

A common reported cause of unwanted horn soundings is a premature earthing out of the wire from the horn going up the steering column.  Either being damaged at the lower steering coupling or within the steering wheel hub.  Or possibly the floating ring in the steering hub is shorting out.

Attached - my crude horn wiring diagram and photos
Cheers
Grant
  Horn wires & steering column pdf.pdf (Size: 111.46 KB / Downloads: 9)
  Horn Wiring Diagram pdf.pdf (Size: 140.94 KB / Downloads: 9)

Update / Edit - from the comments and diagrams posted after this - I now realise my horn wiring has been installed incorrectly all these years !!
See the following for how it should be !!

[Mordred]

An additional pic that might be of use. The early horn connections are painful. 

The thing to note carefully is there is no electrical link across the main shaft across the rubber link like the later one. The cable from the switch goes down the centre of the shaft and then around the coupling. The other thing that causes issues is the rubber coupling that has a conductive strength member through the rubber itself, possibly a steel screen or mesh.  A lot of cheap copies do.  If you can get a circuit between the metal spacers the bolts go through, you will have issues.  OEM quality ones are non conductive.

BTW in the diagram the current flow arrows are shown as running from negative to positive, so if you are using the normal way of thinking the positive is live from the horn to the switch and then earths out through the steering box.  This means the outer of the column is live all of the time so if you touch a loose ground on it the horn will operate. 

Adrian

[Pabloako]

This is where I put the tape, which I used as a insulator.  I found this diagram on Samba and I have marked where I put the tape in blue.

I unbolted the four bolts under area where in ignition switch housing is connected to the dash, which is basically the part that holds the whole assembly to the dashboard and this enabled me to lift everything up by about 20cm, without having to disconnect all of the wires.  
This allowed me to get access to the small electrical tab/connector (Right at the bottom of the outer tube #12, and I sanded that down to get a nice connection on it.  I then created new wire, connected it to the tab and slid ithe down past the steering box.  (This is much easier than trying to get you hand up behind the steering box after it is all put back together again).

I then put one 'wrap' of silicone tape around the bottom of the of the column tube #12 at the bottom, which is the bottom blue line I have added on the diagram.  The tube slots into the cover plate #17 and that has a small plastic ring around it to stop the hole to stop the tube from grounding on the floor.   The tape I added just made sure there wasn't any connection.  

I then put a wrap of tape around the very top of the outer the, however that was more so that the "Retainer for turn signal switch" #5 had a nice snug fit and didn't turn around too easily.  I don't know if this helped wth the horne problem though.

I then put some tape around the very top of the inner column, right where the semi circle metal piece that slots in right next to the indicator arm.  I did this so that it didn't ground against the inner column.    This is the top right blue line.   I suspect that the grounding issue I had was caused by the indicator arm having a negative charge in it and that touched the inner column vie the semi-circle piece of metal and this tape is what fixed my issue.