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MG MGB Technical - Horn button arrangement

I have a (2nd hand) Moto Lita wheel I am fitting to my 1963 Mk 1. The car had no indicator switch so I bought one on eBay. Now comes the challenge of connecting the horn. The indicator has a copper "brush" with a purple wire attached. But the hub doesn't have the brass ring on the back that contacts the brush as shown in some photos I have seen. There is a lucas bullet connector just sticking out of the end of the steering column - looks like attached to a green wire inside the column. Is this original?
I can't find any details of these early arrangements - can anyone enlighten me? Especially if you have a picture or 2!

Thanks
John
John Minchin

There should be a fixed contact on the steering column, that is the brush, which rubs on a brass ring on the back of the wheel as the wheel is turned. My 73 original wheel with horn push has a 'pencil' which is a spring-loaded contact to connect the other side of the ring to the contact inside the detacheable horn-push. It isn't a brush as such as the horn-push doesn't move rotationaly wrt the ring, just in and out as you sound the horn. My Moto-Lita wheel has a wire between the horn push and the other side of the ring, so whilst you can pull the button out of the wheel you can't completely separate the two. That takes the place of the pencil, and is a lot cheaper. It still has the ring on the back of the wheel and the brush contact on the column. On my 73 and 75 the wire that connects to the column brush has a spade connector not a bullet connector. This wire should be purple/black, which carries the ground from the horn button out to the horns, and this was the case from inception until the 77 model year. There wasn't a green wire in the column switch of a 63, just the purple/black for the horn; black, light-green/yellow and light-green/blue for the indicator tell-tales; light-green/brown, green/red and green/white for the indicators; and possible brown and blue/white for the headlamp flasher.
Paul Hunt

Thanks Paul
I had a suspicion that the earlier models didn't have the slipring arrangement.
Could it be that they had a simple wire up the column connection that proved a bit unreliable (due to the constant twisting of the wire) resulting in the change to a slipring.
I will need to see if Moto Lita can supply a brass ring that will fit my wheel
Cheers
John
John Minchin

The earliest switch isn't shown in the catalogue, but the one after that is and does show the contact for the horn ring. The early wheel went on much later than that, so must have had the ring, so the earliest switch must have had the contact. I'd very much doubt it relied on a length of wire being wrapped and unwrapped around the column.
Paul Hunt

John
The parts of these early horn push arrangements are no longer available but they are listed in the MOSS catalogue. You will have to look to the second hand market for a replacement. The alternative is to mount a horn switch on the dash.
Richard Atkinson

In the case of fitting an alternative switch note that in the UK "the horn control ... not readily accessible to the driver" is an MOT failure.

Sometimes developments in cars really are a case of 'one step forward, two steps back'. My 2004 ZS has two fiddly buttons on the wheel. Neither are accessible by finger or thumb while holding the wheel in the recommended manner as they are below one's hands, so you have to take a hand off the wheel. You can't just press your palm on them in the general area as they are little larger than a finger tip and recessed, you have to prod directly on them with a finger or thumb tip. And because they are nearer the rim of the wheel than the centre, if you are going anywhere other than straight ahead you have to take your eyes off the road to see just where they are before you can hit them. Exactly what you don't need when faced with the need to use them! What could be simpler than the large button in the middle? Even the stalk button was better.

And as for the pull-pull dip-switch ... At least the indicators don't use the same system like on recent BMWs and MINIs.
Paul Hunt

"And as for the pull-pull dip-switch ... At least the indicators don't use the same system like on recent BMWs and MINIs."

What is the indicator system on them out of interest? Around here one of the worst offenders for not indicating seems to be BMWs!
Simon Jansen

From a MINI I tried recently one has to pull the switch down, for example, to indicate right, but when you let it go it flips back up to the middle even though the indicators are still flashing. To cancel You have to push it the other way then let it go again. Doesn't sound much, but I found it *very* different to use, and awkward. May also explain why I have seen these cars having turned one way suddenly indicating the other, possibly by the driver erroneously 'cancelling' the indicators manually just after they have been cancelled automatically, as the operation to cancel one way is exactly the same as to indicate the other way!

I've heard other people moan that no-one uses their indicators anymore, but in Solihull mis-use of indicators is probably the most common driving sin. It has got the the point where I ignore what other people are indicating and wait to see what the car does - if I haven't already guessed by the way they have positioned their car before they've indicated! It includes indicating right at a roundabout when they are turning left or going straight on, *still* indicating right when they take the exit (to the left), indicating right to go past some minor obstacle in their lane that doesn't require them to change lanes, indicating one way or the other one or more exits or turnings before they actually turn, indicating left instead of right when they join a major road from a slip-road, and so on. The corollary is only operating the indicators as they turn the wheel to make a turn or lane-change, in the latter case as if the indicator stalk was a magic wand giving them clearance to move into another lane regardless of what might already be there, including a BMW driver getting most irate with me because I didn't slam my brakes on so he could complete his manoeuvre!
Paul Hunt

Problem solved!!!
It's amazing what a thick coat of paint by the DPO can hide. bit of steel wool and 10 minutes effort and I now have a nice shiny brass bush (slipring ) on the end of the column, the new indicator switch assembly on, and the copper plated "brush" contacting the slipring.
I think there should be some sort of bush in the end of the column to hold the contact steady, but I'm sure I can make something to suit.
Thanks everyone for your advice.

John
John Minchin

"I now have a nice shiny brass bush (slipring ) on the end of the column"

The slip-ring is on the column? I.e. doesn't turn as you turn the wheel? The pencil sticking through the boss, going round with the wheel, and rubbing on the slip-ring, makes sense in that context, hence why the pencil is called the brush in some quarters. Any chance of a photo?

I've just noticed a slip-ring and brush in the Parts catalogue, but only from chassis number '219001 on' i.e. from August 70 to the end of the 76 model year which definitely isn't right for the separate slip-ring. Up to Aug 70 maybe, when the wheel changed from the wire spokes to the peforated alloy. After that the slip-ring was on the wheel, the fixed brush on the column, but there was still the spring-loaded pencil inside the boss.
Paul Hunt

Paul
A picture is worth a thousand words!! I'll get some tonight and post them
John
John Minchin

Hopefully this shows the setup. Clearly something is missing fro the end of the shaft - the bullet comnnector needs a bit of locating so that it doesn't short out on the tube . The horn push comes into contact with this connector when depressed.
Cheers
John


John Minchin

Ah, I see. That is a weird arrangement and no mistake! I presume that bullet connector is on the end of a wire that is connected to the brass cylinder. I'd have said that bullet should plug into a connector on the wheel boss, and that should have an insulating sleeve around it, or physically hold the bullet away from the sides of the column at any rate. The actual switch could well be inside the horn-push like it is on the later wheels, the bullet simply being the connection (like the 'pencils' in the later wheels, not the contact which closes to sound the horn.
Paul Hunt

John
Sorry I don't have any pictures - these are the notes I made at the time I had the problem with my horn a couple of years back.

"The centre horn push operates via an electrical connection made between the horn push and a wire located in the centre of the column. This short piece of wire has two, spring-loaded bullet connectors. The other end enters a short rubber ‘tube’, passing through a hole in the metal steering column. This rubber tube is part of one of two rubber sections, formed in curved sections, to wrap around the column and placed under a brass collar – it is this collar that provides the rotating contact for the horn ‘prong’ which has an electrical feed via the indicator assembly"

Richard
Richard Atkinson

That's what I thought. The Moss catalogue diagram is very small and hence difficult to see clearly. As the part is not available I wasn't goung to risk pulling it all apart in case I damaged it. I agree with Paul that I need something to ensure the exposed connector can't short out on the column itself. I can probably get a rubber bung or plug that could push ito the column - with a hole bored through for the bullet connector to poke through.
John Minchin

Richard - so what does the bullet connector on the wire poking out of the end of the column touch or connect to? If it relies on spring pressure from below merely to push it against one side of the switch in the button, like the pencil in later horns, then something does indeed need to locate or insulate it away from the sides of the column. If it is the same as the later pencil, then one end has an inch or so of uninsulated hex brass rod (the moving contact), the other only a very short length of uninsulated hex rod (the fixed contact). This really needs to go a particular way round, as if the long uninsulated end is facing the horn button it can short out on the body of the horn push which is at earth potential. Seems to me it should be the same way up for the early horn as well, although that would still allow a lot of lateral movement. See http://www.mgb-stuff.org.uk/hp.htm for what I mean.
Paul Hunt

In NZ the not long ago changed the rules for indicating on roundabouts. It used to be that if you were going to exit from the left of the roundabout you'd indicate left, going straight ahead you didn't indicate and going off to the right you'd indicate right, all before you entered the roundabout.

Now you have to do all that AND you are supposed to indicate left before the exit you take off the roundabout.

That's fine on big ones but little ones where you're too busy doing other things like steering and changing gear it gets a bit much! And most people don't get it right anyway so as Paul does it's much safer to wait to see which direction the car actually goes!
Simon Jansen

Another common bad practice on roundabouts here is when its two or more lanes and people cutting across them when they are going straight on, usually regardless of anyone else on either of their rear quarters. It's got to the point that anyone who *does* stay in the left-hand lane to go straight on has to watch out for people pulling out in front of them because they've assumed they are taking the first exit, even though they aren't indicating (yet).
Paul Hunt

Paul, I cannot find the old parts in the garage but I had mentioned 'insulating "grommets"' inside the column in a post in 2006. This would make sense as a means of preventing the bullet from touching the column itself. I replaced the original wheel with a motolita one so the mechanism has changed.
Richard
Richard Atkinson

OK, thanks Richard and John for the info.
Paul Hunt

The "grommet" probably only needs to hold the connector steady and insulate it. I don't think it is spring loaded, but depending on the grommet material, there may be some "springyness" when the horn push contacts it.
I think I might be able to get a photo of a '65 car with the original parts in place....
John Minchin

Here is a picture showing the end of the column and the "grommet" or insulated bush in place. It's on a '65 model

John


John Minchin

This thread was discussed between 22/09/2008 and 10/10/2008

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