horn not working

[jboy012000]

Good Morning Everyone on this lovely Sunday morning.

I have a 2008 Berlingo Enterprise Van, with the 1.6HDI engine.

She is booked in for the MOT next weekend, so I was have a quick look at the lights and all the usual suspects and low and behold the horn doesn't work.

I have looked all over but I can't find which fuse is for the horn, does anyone on here have a diagram which shows which fuse to check or change.

Thanks

John

[jboy012000]

Hi All,

I have got a little further. I found my Haynes manual, and found the fuse box diagram, it says that the fuse is F2, 15amp in the main fuse box under the bonnet, the only problem is it doesn't show any F numbers in the diagram only numbers, does this mean I am pulling fuse number 2???

Cheers

John

[jboy012000]

Well, apparently F means fuse, they could have just listed the number as the number, made it a lot more straight forward to read.

I will go take a look next and i'll post how I get on.

Cheers

John

[jboy012000]

Well it isn't the fuse, to be fair, the fuse box looks jack all like the one in the book, so I just tested all the fuses to be sure and they are all fine.

This is a rabbit hole I didn't fancy going down.

Before I start looking for wiring diagrams, is it safe to whip the cover off the steering wheel to check the switches, or do I risk setting off the airbag.

Cheers

John

[geoff]

Hi it is worth having a forum search for horn not working, lots of info listed.

Airbags - best to disconnect the battery to be safe.

Typically the horn doesn't work because the earthing connector under the drivers steering wheel airbag isn't very good, my solution was to replace the push in earth tag with a ring terminal and a self tapping screw.

[jboy012000]

Hi it is worth having a forum search for horn not working, lots of info listed.

Airbags - best to disconnect the battery to be safe.

Typically the horn doesn't work because the earthing connector under the drivers steering wheel airbag isn't very good, my solution was to replace the push in earth tag with a ring terminal and a self tapping screw.

Hi Geoff,

Thanks for the reply, I will take a look at that hopefully this week, I spent rest of today going through the MOT checks, it's amazing what you find lol. Ive spent best part of £70 today just on bits it needs and a couple of bits to improve the way it looks, I just didn't get to look underneath because of the weather.

Thanks again

John

[RattyCortina]

I have the same problem, I looked at running a separate earth to the steering column but found it only worked with the moving part at the base of the column earthed. I am reluctant to mess with the airbag TBH, I am thinking of some sort of brush arrangement to earth the column.

[jboy012000]

What a fun day thats been......

So we started from scratch and tested the fuses again, they are fine, we then took the air bag off the steering wheel and examined the contact points, they were black so we cleaned them up, tested for a good earth but couldn't find one. We tried to run our own earth cable but still the horn didn't work, so we removed the front bumper and tested for power at the plug and found no power was even getting to the horn, so no power and no earth.....

We tested the horn itself with two wires and a battery and it kicked off, so at least we know the horn actually does work.

So it looks like a wiring issue.

I have a couple of questions if anyone could have a crack....

In the Haynes manual it states there is a relay for the horn not just a fuse but (you will like this) it is written that the the location for the relay is unknown, I mean WTF. So does anyone know where this relay is located or have a wiring diagram that we can take a look at.

Second question, Would I pass an MOT if I wired in my own horn button somewhere on the dash to get it working. Or does it have to be the original horn in full working order.

I did get some other jobs done towards the MOT so its not been a total bust, but this horn is throwing me.

Cheers

John

[geoff]

You can have any horn and operating button that you wish to use.

On a motorcycle you can even get an mot with a bicycle bell

As long as yout vehicle can emit an audilbe warning you get your ticket.

Wiring issue, did you get voltage at the airbag contacts ?
Just wondering as this would indicate where the supply / earth return issue is.

[jboy012000]

You can have any horn and operating button that you wish to use.

On a motorcycle you can even get an mot with a bicycle bell

As long as yout vehicle can emit an audilbe warning you get your ticket.

Wiring issue, did you get voltage at the airbag contacts ?  
Just wondering as this would indicate where the supply / earth return issue is.

Hi Geoff,

I will be honest we didn't want to mess around with the airbag off, we thought with it disconnected if we put the battery back on it might go into limp mode or we might need a computer to get the van running properly again, so we couldn't try anything with a multi meter to test for voltage on the steering wheel. I hate messing with airbags

Thats good news about the MOT though if worse case scenario I have to wire up a push button on the dash or put one of those cool gear knobs on with a push button on the top (very james bond), it will be a lot easier that messing with the original wiring which is just impossible to trace through the vehicle.

A plan for another weekend

Cheers

John