Electrics …. Am I missing something…?

[Just smiffy]

Now I’m the first to admit that I’m rubbish at lecky but this has got me flummoxed

the horn wasn’t working on my car so I got a new one, I’ve got 12.76v at the end connectors on my meter when the horn is pressed but nothing if I put the horn across a spare car battery I have it makes me hit the shed roof

so…. Why does it not work on the car..?

 

[Landy Andy]

Is the switch an earth or neg switch?

 

[Just smiffy]

Is the switch an earth or neg switch?

I’ve swooped the connections still nothing… the horn works whichever way I connect it on the spare battery..?

 

[Landy Andy]

The connector that goes on to the horn has what at the terminals when horn not in use?
Possibly it has 12v and nothing as the switch connects to neg to operate. That is how they used to be wired.

 

[berni109]

Are u only getting voltage when the wheel is pressed? Or is it permanently live? Sounds (u should be so lucky) like an earth fault.

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[Just smiffy]

Right, if I put my multimeter on just the connectors red-red and black-black I get 12v when the horn is pressed, if I connect them to the horn and connect the multimeter then press the horn there is no voltage…

 

[Just smiffy]

Are u only getting voltage when the wheel is pressed? Or is it permanently live? Sounds (u should be so lucky) like an earth fault.

No voltage until I press the horn

 

[Landy Andy]

Put the live to the horn and then add a wire joining neg to chassis or earth point and what do you get when you press horn?

 

[Googlebot]

Bad earth.

Check again with a known good earth as Landy Andy suggests.

 

[Just smiffy]

Put the live to the horn and then add a wire joining neg to chassis or earth point and what do you get when you press horn?

I’ll go do that..

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[DBK]

A poor connection somewhere. You could try a rig up a temporary earth lead and see if that makes it work. If it doesn't then the fault is in the positive side.

Landy Andy beat me to it.

 

[Lenny HB]

Another possibility it could be the relay that switches it, that's if it switches the live side.

 

[JJ]

Some German vehicles link the horn with the brake lights... if the brake lights stop working the horn won't work...

JJ

 

[Lenny HB]

Some German vehicles link the horn with the brake lights... if the brake lights stop working the horn won't work...

JJ

I think it's a classic mini not a German one.

 

[chatteris]

you might have over 12v but not much current we use a couple of bits of wire connected to a headlight bulb if it wont light the bulb when you earth the other wire you have a bad connection on the 12v side

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[JJ]

I think it's a classic mini not a German one.

Don't the Germans make minis these days?

JJ

 

[Just smiffy]

Tried a new earth to the chassis from the horn… nothing I get good voltage from the connectors when horn is pressed but I I connect the horn up I get no voltage..

I did say I’m crap at lecky…

 

[Vipar]

Spooooooky

 

[ambulancekidd]

Did you have an intermittent problem before buying the new horn? Is this one of the "new Train Horns"?

 

[chatteris]

Tried a new earth to the chassis from the horn… nothing I get good voltage from the connectors when horn is pressed but I I connect the horn up I get no voltage..

I did say I’m crap at lecky…

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no current then, a bad connection on the live side

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[DBK]

Tried a new earth to the chassis from the horn… nothing I get good voltage from the connectors when horn is pressed but I I connect the horn up I get no voltage..

I did say I’m crap at lecky…

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That is progress. At least you know what side to look at now. But as Lenny suggests if there is a relay involved you need to find it and I think for a few pounds just replace it and then see what happens. A Google for "where is the horn relay for my Mk 1 Wartburg*" might help.

* Insert actual car model here of course.

 

[jockaneezer]

Sounds like a corroded terminal somewhere, it'll allow you to read the voltage, but isn't up to supplying the current (amps) to oscillate the horn (ooer missus !)

 

[Realist]

Keep the horn, scrap the car lol

 

[Just smiffy]

Bloody electrics….

I can and will be stripping this mini down nut by nut and putting it back together again I’m good at fixing mechanicals but all my life I could never get my head around the sparks, I’ll have a go but too many shocks in my time tends to put me off…

I’ll take it to my local sparky…££’s

 

[Just smiffy]

Did you have an intermittent problem before buying the new horn? Is this one of the "new Train Horns"?

Horn didn’t work from the off… replacement is just a Chinese cheepie…

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[bertiebasset]

Horn didn’t work from the off… replacement is just a Chinese cheepie…

Or not Cheepie as you have found out

 

[chaser]

Or not Cheepie as you have found out

Can't blame the horn if it works on a battery

 

[Abacist]

Mt thoughts are that the original horn was a low amp teeny peep, peep sort of horn. Many horn replacements require heavier duty cables from the battery to the horn with a relay introduced to connect the horn push to the relay. You should be able to Google wiring a horn and relay into the car wiring for a mini.

If the horn is heavier duty that the one it is replacing you have probably blown the horn fuse when trying it so that now needs to be replaced.

 

[rangi]

Just run a new set of wires Gary, had the same problem with the VW T4. Seems the wire running down thro the Steering column was earthing. Probably be able to find the original source in the Fuse box to connect to, to get power,

 

[Badknee]

My suggestion would be to insert a relay into the equation. Connect your known good earth and live to one side of the relay then run a larger cable from the battery through a 20amp fuse through the switched side of the new relay to your horn.
Press the horn and a low amp supply switches the relay.
The high amp supply goes straight from the battery to the horn.
Stop pissing about and get a decent horn.

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