Horn Not Working - Help!

[iPlod999 143 1 Cars]

Nope still no good.

 

I'll have to give it another go tomorrow.

[jackherer 543]

No. 12 V plugged in.

 

I just re-read that, do you mean there is 12v with it plugged in or there is not 12v with it plugged in?

[iPlod999 143 1 Cars]

I get 12 V when the plugs are off.

 

Once they are plugged onto the horn. Zero.

[jackherer 543]

Ah OK, I misunderstood earlier. This is actually very typical for 205s and the multimeter just adds confusion by showing voltage when the horn or whatever still doesn't work.

 

The wire is supplying 12v but as soon as you apply a load (the horn) the voltage disappears. This is almost always because the wire is old and corroded, its electrical resistance is high so a little bit of power can get through when it's unplugged which is what you see on the meter but as soon as the horn tries to pull some actual power through it the resistance stops it.

 

Like I said before you need to cut the wire out bit by bit until you find shiny bright copper then splice new wire in. Peugeot mention something called a solder sleeve in Service Box so IMO they are an OEM repair method, you need a heatgun to use them. http://uk.rs-online.com/web/c/cables-wires/cable-accessories-ties-tools/solder-sleeves/

 

This is a common problem on 205s, not just for the horn but all the exposed wiring, lights, washer pump etc.

[iPlod999 143 1 Cars]

Schoolboy error time.

 

When I was testing last night with the wiring plugged on to horn. I was putting the mm on each of the 2 horn terminals.

 

Brain wave today at work and I just put 1 probe on the horn and earthed the other via the wing.

 

There is power going to the horn when the stalk is pressed.

 

When I connected the horn direct to the battery it went beeb.

Edited July 29, 2014 by iPlod999

[jackherer 543]

That suggests a bad earth then, when you put the meter on the wing it is earthing directly. You would see 12v at the two horn terminals if the supply AND earth both worked, by earthing the meter directly you are then only testing the supply which you've proved works.

 

Put the positive multimeter probe directly on the battery + post and put the negative probe on the earth terminal plug on the horn, you should see 12v but if the earth is faulty you wont.

 

[iPlod999 143 1 Cars]

Ok starting to sink into this head of mine.

 

+ of battery to wing showed 12v.

 

+ of battery to earth wire showed zero.

 

I'll replace the short earth wire between the horn and the earth point behind headlight.

 

This.

 

 

Out with family tonight. So will try this in the morning.

 

Thank you Kieran and Welshpug so far.

[iPlod999 143 1 Cars]

Success at last.

 

 

Replaced the short earth wire and put on new connectors.

 

Can't wait for my next bit of road rage.

 

Thank you again for the help guys.

[jackherer 543]

Nice one

 

You'll know what to do next time your sidelights/foglights/washers or even the horn stops working five minutes before the MOT too!

 

The video is private BTW.

[iPlod999 143 1 Cars]

Try the video now.

[mmatthej1 1]

Relay for airhorn - can anyone guide , plse?

Relay for airhorn - can anyone guide me as to where it is located , plse?

[jackherer 543]

On the nearside of the bulkhead, either screwed on directly or in a black plastic box on later models.

[mmatthej1 1]

Thanks! Will have a search, when (if) rain ever stops!