guys, my horn has stopped working, with the standard wheel on it was a little funny had to hit it in the right spot for it to work,
and when i swapped it to a momo seude wheel with momo boss, it worked once and never again,

so checked fuse, HAZ HORN is fine,
realyu was still clocking upon pressing horn, so just incase i changed the relay with a toyota genuine one,
Still clicks but no horn,

checked power with test light, power goes to relay, but no power to horn conector, and horn no work, so im thinking, there may be something wrong between the relay and horn, but i have no idea im not good with electronics,
can anyone help?

When you press the horn. It creates a earth. There is no positive power going to the horn.

so how would i fix this issue?

Check that the horn connector is earthed. Just the bit on the steering column not the bit on the wheel
 

how would i do that, 
sorry to be annoying, 
would i have to pull the coloum apart? or..

Ok the wire that goes to the horn button unplug it. You might have to remove the wheel or just pop the center horn button out if it does.
To find if a earth wire is earthed is just like finding a 12v wire but in reverse. Hook the red wire to something that has 12v and the black wire goes to what you are tiring to test.
 
Or you could just touch the wire coming out of the coloum to a metal part of the boss kit and the horn should go off.

Ok Guys this is really annoying me

So I've tried to fix this issue today,
Number one
Pulled the horn apart
I have the 92 aus spec no airbag with the brass ring I think the mono hub I got was
C7715
From momo

Now It had a wire that comes from the brass ring to connect to the back of the wheel
But the wheel has two connection points which means it's not internally grounded right?
So I've connected the brass ring wire to the one connection
And the extra wire with the wheel kit to the column itself like the instructions
And relay clicks but still no horn am I mission something? Do I have to earth something it's really ****ting me off

Someone help me

Why dont you just systematically test the system. 
 
eg:
See if you are getting power at the horn when button pressed/wire earthed?
Unplug horn and supply direct power and earth to horn see if it works?
 
This way you can chase it back to see where the failure is.
 
Cheers
 

Momo C7715 is the right hub to replace the stock MR2 slip ring type S/wheel. I have one on my '90 model.
 
Do you have a stock slip ring wheel to put on to test it?
 
You could use a multitester to check for 12V between the spring loaded connecter* and earth with the wheel removed, or simply short it to the center shaft (earth)
(*The connector that touches and rubs on the horn ring when the wheel is replaced)
 
 
 

All, good think i sorted the issue, it was because everytime i tried the horn with the wire conected i had it sitting on the plastic tray instead of grounded to the chassis rail it is meant to be bolted to= not completing the circuit.

I will test this theory tommorow.

Redtarga,
the horn ring dosnt that earth to the little thing sticking out of the column and that keeps a constant touch on the ring even whilst turning, as on the ring it has a wear mark from the little knoby thing protruding from the column

but im getting power to the horn, because it causes te realy to click, and its not negative switching,

but the issue, was no power going to the horn, and the horn works as i tested that today, and it BEEPED ahaha!

But i realised i never had the horn grounded so it was never completing the circuit, which would explain why it was very intimitant because when i pulled the horn off the was very looose as the bolt was threaded in a few turns and the horn was just rattling around probably coming un grounded at some points.

i feel like such an idiot after spending many hours and frustration as to why this didnt work, and it looks like its was all because the horn was not grounded.. ahha

Thanks for everyones input, really appareciate it!