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steveyorks

Well-Known Member
A past owner has fitted a switch on the dashboard for a horn and it lights up when pressed but the switch itself is just a switch and so would stay on unless you turn it off as opposed to a proper horn switch that only stays on while you keep it pressed in. I have bought another proper switch with two terminals to swap it over but am not sure which wires I use from the current set up. Obviously I don't need a light on a switch to tell me the horn is going off! Looking at the back of the switch there are 3 terminals, one is obviously an earth but the other two, I am guessing are a live for the horn and one for the light on the switch? Can anyone tell me which I use for my new two terminal switch or how to find out which I use please?
 
I can sort a pic but the earth wire is yellow/green and the other two both red. Don't think a pic would be of much help.
 
steveyorks said:
I can sort a pic but the earth wire is yellow/green and the other two both red. Don't think a pic would be of much help.
Click to expand...

if u use a multimeter u should be able to trace what wire is which

the two red wire i imagine are live in live out , so have power from the fuse box, wire into the switch , then a wire live out that is connected to the horn

put a multimeter on the back of the switch to find the live in , other live out , last wire should be an earth , however best not to trust a colour of a wire, put ur sidelights on, use ur multimeter onto that green and yellow wire to ensure it doesn't become live

hope that helps and makes some sense
 
It should be written on the switch what pin is what or sometimes the earth pin is a different colour.

But if your have taken the switch out and can get to the crimps behind it, unplug the green/yellow cable make sure it's not touching anything metal and turn the switch on.
If the horn sounds the green/yellow is your earth so it's the two reds you want on your new switch.
 
how ever you find out which is your earth wire please make sure there is not chance of it touching anything live behind the dash.
 
Mcclegend said:
how ever you find out which is your earth wire please make sure there is not chance of it touching anything live behind the dash.
Click to expand...

it certainally makes u jump when u realise there's a stray earth and touches a live, all u see is a nice flash along with hunting out which fuse blew, lol
 
gstuart said:
it certainally makes u jump when u realise there's a stray earth and touches a live, all u see is a nice flash along with hunting out which fuse blew, lol
Click to expand...

Sorry for going off topic Steve but it's landyzone.

Ive heard of farmers round here if there paranoid enough wire up there trailers wrongly and add there own earth so if someone tries to steel it they try and do as much damage to the thieves as possible, brake lights straight to earth and stuff, I bet it makes a right mess.
 
Mcclegend said:
Sorry for going off topic Steve but it's landyzone.

Ive heard of farmers round here if there paranoid enough wire up there trailers wrongly and add there own earth so if someone tries to steel it they try and do as much damage to the thieves as possible, brake lights straight to earth and stuff, I bet it makes a right mess.
Click to expand...

no probs and never a need to apologise , don't think any thread will stay on subject and do it all the time , it's gary by the way , lol

can't blame the farmers if there items are getting nicked time and time again

surprising what some building sites do to protect machinery etc , i.e. using power packs, etc
 
Hi, on a standard switch there is no earth, supply in and supply out. The earth will be supplied for the bulb part of your switch. The easiest way to check supply or neg is with a test light.
Connect one side of your light to a know earth and tap the wires with the other end, when the bulb lights up that's your supply in, therefore the other red is supply to the horn
Test lights are far better than multi meters on vehicle electrics
Hope this assists
 
Diesel techy said:
Hi, on a standard switch there is no earth, supply in and supply out. The earth will be supplied for the bulb part of your switch. The easiest way to check supply or neg is with a test light.
Connect one side of your light to a know earth and tap the wires with the other end, when the bulb lights up that's your supply in, therefore the other red is supply to the horn
Test lights are far better than multi meters on vehicle electrics
Hope this assists
Click to expand...

oh no there not , lol, joking aside bulb can indeed be an easy way to trace wires etc , in certain situations

however i have to gracefully disagree theres no way a test light can be better than a multimeter on vehicle electrics , light cant help u with what volts , amps or ohms readings

simply testing a maf sensor , u wouldn't be able to test that with a bulb method
 
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