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MG MGB Technical - wiring for horns

I'm rebuiding my 67 MK1 GT and have purchased a complete replacement loom for the car, since the original was completely shot and had been heavily modified in a dangerous manner. As far as I'm aware it's from a reputable supplier and is labelled as a 3-sychro GT.
I've got round to the frontal area where the headlights / sidelights and horns are connected.
The problem I have is that there appears to be only one pair of wires for 2 horns.
Can somebody please explain how I wire up for the twin arrangement? Do I have to make up a feed over to the other horn or should it already exist within the main loom?
If someone has a photo this would also be very helpful.
Thanks in advance,
Nick.
Nick

AFAIK the wires should be there in the loom.

Pretty sure my '67 roadster has them in the loom and not an extra.
Dave O'Neill 2

Nick - The two wires are daisy chained from the first horn to the second. The original horns had double spade lugs for this purpose. The wires coming from power and the horn push attach to one of the lugs on the first horn and then another set of wires run from the second lug on each side of the first horn and run across the front of the car, under the slam panel to the second horn. Check under the slam panel for that second set of wires that run from one horn to the other. Cheers - Dave
David DuBois

Nick

This is from Rick Astley's old web site


Power from the Batteries (3) goes to the Fuse Block (19) via a Brown wire. From the fuse, a Purple wire supplies power to the Horns (23). If the Horn Switch (24) is closed, current can flow from the power source through the Fuse (19), the Horns (23), and from there through the Purple/Black wire, the Horn Switch (24) and via the Black wire to ground.



DK McNeill

Thanks for the advice and very helpful reference to Rick Astley's website.

I've made up a connecting harness between the two horns by using part of the old loom - looks and works fine!

Cheers,

Nick.
Nick

My 73 and 75 only have two spades on each horn, i.e. one spade for each connection, which means two wires in one spade for each connection on the right-hand (facing forwards) horn and one wire in each connection on the left, the wires between the two going through the main harness along with the lighting wires for the left-hand side. If earlier horns did have separate spades for each wire it would mean four spades on each horn, or the right-hand one at least. Not to be confused with 77 and later which only had one connection and one spade on each horn! But at the end of the day David is correct - the wires (or wire) was daisy-chained from the right-hand horn to the left.

I'd be surprised if this isn't the case, but if it isn't then I'd reject the harness as not fit for purpose.
Paul Hunt

My '67 still has the original horns and they, too, have 4 spade connections so that the power is delivered in parralel. RAY
RAY

I have just spent the past couple of days trying to get the horns working on my 64 Mk1 Roadster. (Believed to be the third oldest Aussie built one still alive on the road!!)
After it dawned on me that the horns work on a live permanent current set up. You must make sure that you do not earth the centre bolt and bracket fixing as this will allow current to flow through the horns and cause them to sound. It is actually by pressing the horn button that an earth is introduced to the circuit causing the current to flow and the horns to sound, I was stumped for a while as I thought that pressing the horn button allowed positive current to flow to the horn and it would naturaly pass through the horn and earth on the second wire/terminal, but as I now know this is not the case.
Craig Jenkins

This thread was discussed between 23/05/2009 and 21/06/2009

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