[mikedonnelly]

Hi there, only been driving a year so don't know much about cars and want to try and fix things as cheaply as I can if possible. I have a 2001 hdi 90 and the horn has stopped working, I've changed the fuse in the engine bay but still nothing. Anything else I should or could do, any help greatly appreciated

 

[jimmymarsbar]

The comms unit may be faulty (that's the unit that sits immediately behind the steering wheel where the indicator and light stalks sit in to).

 

[mikedonnelly]

How would I go about checking this? Would I need to remove the steering wheel?

 

[madbadandold]

The horn not working is a bad earth on the horn mechanism under the airbag. There is a write up on how to take it off and clean the contacts and it literally takes no more than half an hour without getting dirty hands to,so a bonus.
Do a search on the forum for past reports and fix.

 

[mikedonnelly]

I've found info on an old thread so gonna try it tomorrow. The airbag won't blow on me tho will it lol

 

[WillNZ]

Disconnect the battery before carrying out any dismantling of the steering/airbag unit.

You must let the BSI go to sleep before you disconnect the battery though. Plenty of info on here about how to let it sleep and then disconnecting the battery.

 

[Brilec]

Have you checked the horn itself? On mine the connection on the horn had rusted which stopped it working.

 

[madbadandold]

Access to the horn is more awkward than doing the check on the steering wheel as it is right up in the left wheel well behind the bumper and wheel arch liner. The steering wheel fault is a KNOWN defect. It was on the car I got anyway and the forum made it easy.

 

[mikedonnelly]

I haven't bothered going in through the steering wheel just put a multimeter to the spade connectors of the horn and there is power going to it so just gonna buy a new horn (5.99 eBay) if that fails will go through steering wheel. Was told to exhaust all my options b4 messing with the airbag

 

[madbadandold]

The airbag is not a worry Just disconnect the battery after first releasing the bonnet,open the drivers window and turn the key off. Then wait 15 mins and all is good and safe. I like to disconnect both cables, earth first. Just because it has power does not mean that the horn push is OK as the earth is the operator of the circuit!

 

[WillNZ]

The reason you put the BSI to sleep/disconnect the battery before doing any electrical work on the car is, if you disconnect electronic systems/sensors etc with the battery still connected, it will trigger faults. Some of these faults can only be cleared using PP2000/Diagbox and can affect the running of the car if not cleared.

This apart from the fact that airbags can be triggered accidentally if the whole system is still powered up..