Horn. not working

[Painter16]

While driving down to Cornwall yesterday I needed to use the horn ,it’s didn’t work,no idea why ,everything else seems ok,any ideas folks thanks.

 

[Tony Dyson]

A, You didn't press the button hard enough ?
B, You didn't press the button long enough ?
C, There is a fault on the electrical supply circuit and it's blown the supply fuse?

So if you think you pressed the button hard and long enough? check the fuse?

 

[Painter16]

A, You didn't press the button hard enough ?
B, You didn't press the button long enough ?
C, There is a fault on the electrical supply circuit and it's blown the supply fuse?

So if you think you pressed the button hard and long enough? check the fuse?

Lol will check fuse hopefully that’s all it is ,trouble with me I allways think it’s going to be something more than just a fuse

 

[M80]

Corrosion at the horn/s connections would be my starting point.
Manipulate the connections on one while someone presses the tooter.

 

[Tony Dyson]

Lol will check fuse hopefully that’s all it is ,trouble with me I allways think it’s going to be something more than just a fuse

When it comes to faultfinding, one golden rule is 'Never assume, it will invariably make an 'ass' out of 'u' and 'me' you may be very well right and as M80 above has suggested it may also be a corroded connection but you first of all need to confirm you have a healthy supply to the circuit, then you can work on the path to the horn.

 

[Blobcat]

Corrosion at the horn/s connections would be my starting point.
Manipulate the connections on one while someone presses the tooter.

Just be careful when you do that… the horn is surprisingly loud when you’re right next to it…

 

[M80]

Just be careful when you do that… the horn is surprisingly loud when you’re right next to it…

You could put the cat on the bonnet as a visual indicator, but then who's going to manipulate the connections?

 

[EmilysDad]

The easiest check is to remove the horn from the car & apply a known 12 volts across its terminals. Does it work? If not, replace.
If it does, then the you need to check that the loom itself is OK and supplying 12 volts when the horn push is pressed. On a previous car of mine, one of the horns packed in ... the convoluted conduit had chaffed through the wires to the horn. ....

 

[brandwooddixon]

Usually its the horn.
They don't get used much (unless you're Italian) and tend to be hidden away in places that get damp and dirty.
Often there are two of them, a high and a low tone fitted in different locations, such as behind the bumper / fog lights.
Unless you're an MB fanatic you don't need to buy MB branded replacements.

 

[EmilysDad]

.....
Unless you're an MB fanatic you don't need to buy MB branded replacements.

The original horn on my Smart is as effective as a fart in a Beanz tin .... I fitted a pair of cheap (£6 or £7) from eBay and they've been great!

 

[Blobcat]

The original horn on my Smart is as effective as a fart in a Beanz tin .... I fitted a pair of cheap (£6 or £7) from eBay and they've been great!

I agree... first thing I did was change mine…

 

[SL63 Mark]

You could put the cat on the bonnet as a visual indicator, but the do agree about the conecten who's going to manipulate the connections?

Our cats won't stay still, no matter where you put them. It could be the actual horn itself. Usually they are in an exposed position and suffer from road salt.

 

[Painter16]

So checked fuse not that found the 2 horns behind the grill ,guy From next door took off leads to both put test meter on.both dead as a dodo ,****** raining so just wait for it to knock off

 

[M80]

Relay?

 

[Painter16]

Relay?

Think that’s next but I’m not sure which one it is ,diagrams aren’t the best,

 

[M80]

Think that’s next but I’m not sure which one it is ,diagrams aren’t the best,

Aye, I deciphered the info within the manual for the 639 years ago. I created a spreadsheet in easy to understand form for if I'm in a dark place trying to diagnose an issue while on the hoof.

On earlier 639's it was a narrow grey relay,
by 2014 that had become a narrow black and yellow relay.

 

[Painter16]

Not even sure which box it’s in passenger side box or drivers side

 

[M80]

Sorry I don't know your mo mo,
over to the more knowledgeable for that.

 

[mattkh]

So checked fuse not that found the 2 horns behind the grill ,guy From next door took off leads to both put test meter on.both dead as a dodo ,****** raining so just wait for it to knock off

Sooo your kind neighbour took off the plug to one horn and put the test meter on it..
Who was inside the car pressing the HORN,,?

 

[EmilysDad]

So checked fuse not that found the 2 horns behind the grill ,guy From next door took off leads to both put test meter on.both dead as a dodo ,****** raining so just wait for it to knock off

Have you tried putting power directly to the horns?