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MG Midget and Sprite Technical - Steering Column Switch Incorporating Horn
|Hi.I have a midget MK 3.After using a toggle switch to operate the horn just to pass the MOT... I agree not the best way to operate the horn but neither was the original horn push.
I decided to fit the switch that came off a friends mini which included the horn push.Bullet connections had to make way for spade type.
Connected up lights,indicators and dip everything worked except the horn.Gut feeling earth/ground problem.
Looking at the archives Nigel mentions the earth strap on the steering column to rack, looking at mine it doesn't seem to have one.
But on the original push button horn which I think is known as a 2 way wire system would it need a strap.
Am I now reverting to a 1 wire system and have a need to earth the column to rack,
Looking at my steering column there is shortage of places to connect the strap to.
Also would I need to change the connections at the two horns.
I would appreciate your thoughts.
Thanks for looking.
|S, I had exactly this problem earlier this year.|
A short link from the bolt securing the steering column end cap to the mount solved it.
There are several good photos which might help on this thread: http://www2.mg-cars.org.uk/cgi-bin/or17?runprog=mgbbs&mode=archiveth&archiveyear=97_2017.dat&access=&subject=97&subjectar=97&source=T&thread=2017030814180919167
The link doesn't seem to want to work so I've reactivated the "Steering Column Earthing" thread.
Hope it helps.
|Thanks for the reply Colin.
Looking again at the steering column & rack it is of the type that was fitted between 1972-79 and no earthing points that I can see.Except a plug on top of the rack used as a oil/grease point.
There is a strap fitted of the woven steel type but this is on either side of the engine mount.
There is no outer metal sheaf on the column until it reaches the bulkhead.
I have a spare earth strap ( compliments of the army 30 years ago) so finding a location is the problem.
Looking at the switch/horn stalk there is two wires entering the switch.One is solid purple which a previous post advised is for the headlight dip.
The other is the purple/black tracer which is the horn connection.
The solution for the earth maybe at the wheel end of the column.
|Midget Mk3 is technically anything after 1966, so covers quite a wide range.
What is the age of your car?
Some late models had the horns switched live, whereas earlier cars were switched to ground.
The switch you have there would appear to be more suited to the late model, as it seems to be a 'live switching' version, due to it having 2 purple wires and one purple/black.
One of the purple wires (far left, under the blue/white) is the supply for the headlamp flash. The other purple wire in the middle would be the live supply to the horn switch, then the purple/black supplies the switched 12v to the horns, which are then grounded after the horns.
Assuming that your car is the earlier, ground-switching version, you will need to connect one of the two wires from the switch to a suitable ground, unless you really want to rewire the horn circuit to the later type.
For simplicity's sake, it would probably be best to connect the purple/black to the other purple/black, then the purple to ground - as long as you get the right purple wire. It would be a good idea to fit some black heatshrink sleeving to the purple wire to identify it.
BUT - please do first check which version of horn wiring your car has.
|Dave O'Neill 2|
get your Driver's Handbook out, purple is horns and interior and boot lights. Headlight dip is blue with red tracer (I've just checked) and I don't know but can't imagine it'd be different on a Mini.
The solid purple wire is from the fuse box and purple/ with black tracer goes to earth.
On my car I have a heavy duty toggle switch which I've not bothered to replace and that has the purple/black going to the heavy duty toggle switch and on the other side of that switch a wire going to the car's body for earth. (As with all connections and wires) you want a nice clean, secure and protected earth wire and connection.
There are some posters on here that know all about car electrics but I'm not one of them. Can you not use the wiring set up you had before but using the stalk switch instead of toggle?
|I was adding to my post but as usual missed the Edit guilotine
I don't know but can't imagine it'd be different on a Mini.
(ETA: looks like I was wrong).
There are some posters on here that know all about car electrics but I'm not one of them.
(ETA: like Dave).
ETA: I was typing whilst Dave posted, he put some of what I thought about posting, i.e. the more info you give such as putting up your Vehicle Profile for viewing, the quicker and more accurate the answers could possibly be).
BTW the 1500 is also a MK3 AFAIK
|Thanks for comments I will try and digest the info.like most electrics are foreign to me.
I will try and update my profile.
Nigel I took your advise on a previous post and purchased a new MK 3 owners handbook from Junction 59 Classics ( Darlington) £6 which I thought good value.
Dave it is a MK.111. Registered 22/03/1974
Fitted with two horns both have two terminals each and connected to each is one purple wire and to other terminal purple/black.
The purple/black wire going into the horn stalk at the switch is that classed as a earth.
|On your car, the purple and black would Earth the horns through the horn push and the column. |
As you are no longer using the horn push, the column doesn't need earthing. What does need earthing is the switch, which is now on the stalk.
You have two wires connected to the stalk switch - one of them needs to be connected to the purple/black from the horns the other needs connecting permanently to ground/earth.
|Dave O'Neill 2|
£6 is a very good price, you'd need a very late round wheel arch, chrome bumper handbook - well one for a 1973-74 car or the regular reprinted combination handbook (AKD 7596 (6th Edition)).
My car was registered a year before yours so originally would have been just about the same but even then there would have been a few small differences between our cars, including the engine, and our cars would have lots of differences to earlier cars.
A tip with the horns, wipers and most things on the car is to test them regularly to keep them working as well as to test they are, easy way to do that is to drive the car regularly on reasonable distances journeys all year round. Winter often has some of the best driving days, even hood down, dry and sunny.
Er, just noticed you're Durham, lovely area but perhaps less dry, sunny, warmish winter driving opportunities (?). :)
|Raining cats & dogs here today Nigel.
Just back in.
I shaved the purple wire at the switch and touched it to earth/ground .. blown fuse.
Replaced fuse, tried the same with the purple/black wire but no result when the stalk was pressed.
A moment of doubt so using a test lamp (normally used for timing) I put it across both wires and pressed the stalk .. nothing no light..
Have I been given a dud switch.
If I have i'm not annoyed with the lad that gave me it but with myself for not testing it thoroughly.
|Think I got that wrong, if I put it across both wires I bypassed the switch so the bulb should of lit. The bulb is good.|
Try again tomorrow.
I'll leave the electrics here to Dave and others, I thought you'd just need to connect the purple black to the earthing wire formerly on your toggle switch BUT DON'T trust my thoughts on it. A good connection is needed - except when touching lives then the merest touch will have the fuse of course.
Do check your purple wire connections a bit of muck can change a purple wire to appearing as a purple/black wire and other colour traces can change in appearance.
Could you do a non-live/disconnected continuity test on the stalk horn push with its purple and purple/black wires and stalk horn push well, er, pushed just to test that the stalk horn push actually works.
I've made up a set of long wires and various options of connectors that I use to test items directly off the battery posts (previously with a 12v bulb until I dropped it) as fault finding and testing before I fit them (when I remember).
I tested my first electric cooling fan this way to check it worked and it did, but I forgot to check which way it made the air go and did find out until I used the car that they'd included the wrong fan in the kit. I had to stand on my head, holding a magnifying glass trying to read the small print fan model number whilst looking through the fixed rad grille before the manufacture would believe it was the wrong fan.
Nice looking car you have, sits well, nice to see reflective plates on it too, saw a 'W' reg Mini the other day on b&w plates, looks so wrong to me.
ETA: periods of warm sun here and quite muggy
This thread was discussed between 03/09/2017 and 05/09/2017
This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.