Unusual one here!

Have a really bizarre problem. Am trying to install a horn as my car doesnt have one fitted. Using the black and yellow wire. When i turn on the ignotion the horn constantly sounds! Have disconnected the wiring from the stalk it still sounds have removed fuse it still sounds have removed horns relay and it still sounds! Whats going on!!
Its really irritating haha!
Could it be anything to do with wipers and blower not working? Have checked the x relay number 17 and it clicks when ignition turns on so assume this is working, and the wipers relay is 99 would that click also to indicate if its working?

Are these things connected to the constant horn sound?

Horn relay is usually at position 6.
Not sure on your tin top.
Remember though these are negative switched, not from the positive side.
So it sounds like they are permanently wired to earth or live.
The horn push just shorts the negative together to sound the horn.

thanks for your response, have fixed the blower and the wipers was a bad relay (17) opened it up and soldered a broken connection so those are all functioning fine.

Havent figured out the horn earthing switch so thats still blowing like no ones business! but least i know the blower and wipers issue isnt connected with the horn now.

Good grief this electrical stuff is hard work i tell ye!

Just seen you got a cabby lol.

It could be the relay stuck on then, number 53 if I recall.

So pull it out from the box.
It could be corroded inside.
A common problem with these cars is dirty contacts etc on the relays and the fusebox.
Just check to make sure you haven't got any water ingress, from the windscreen corners, any loose grommets in the engine bay and the rubber drain tubes either end of the scuttle are clear, other wise water can fill the tray area and leak down the blower motor etc .

Also check the the connections inside the horn its self, the centre of the sterring wheel

Thanks for both your responses, have since made abit of progress…

The constant horn sound has gone now this was due to an earth wire being stuck! Have freed it so that the switch works corrctly.

Still a problem however!

Have checked relay 53 and it clicks and have tried swapping for another 53 relay and the horn just makes a very faint half hearted attempt to sound now when i press the button.

This is a brand new horn ive got so it shouldnt be the horn itself and as of the previous problem it definitely works!

My steering wheel isnt original it looks as though it could be a MOMO, have taken it all apart and put back together and traced the earth for the horn which is spliced onto the brown and blue earth switch wire on the fuseboard? Is this correctly wired?

Not 100% sure on that but one side goes down to earth via the column to the wire at the bottom of the column to the rack.

So it's a case of tracing them back with continuity tester.

Thing is on these cars they were fitted with a twin horn set up. Over the years the wiring deteriorates and the voltage/current drop becomes enough to fail to sound both horns.
If you tried connecting both individually to the battery they sound healthy, however on connecting back up, they either wimper or fail. Try disconnecting one horn and see what happens, if it sounds loud, swap over to the other side if that sounds loud then that's probable cause. The other way is to wire in another relay so the horn sounds direct from the battery, if that makes sense. I just left one disconnected and the horn is loud enough.

run a wire from the battery +ve into the back of the yellow/black wire on horn, then try the horn again. if its nice and loud the live feed for the horn is bad. if not its the relay, fusebox or earth wire at fault.

with the horn switch, remove the wheel and use a screwdriver to earth the little tab on the stalks to the column. if it sounds nicely then the steering wheel wiring is at fault, if not then check the column earth in the engine bay, its a short wire from steering rack to chassis

Thanks Rubjonny, this worked a treat and i got the horn sorted