Electrical Experts - Horn Inoperative

[E30Adam]

Touring failed it's MOT today on the horn not working, can you believe it!!

I spent all morning trying to figure out why it wasn't working. I tested all the electrical tests as stated in the Bentley manual and all was as it should be. I also checked the earths from the plugs that go into the actual horns and they were fine. There was however no power getting to the other teminal on the plugs that go into the horns.

I tried a differnt steering wheel and it still didn't work so I'm thinking it's probably a problem somewhere between the steering column and the fusebox.

Can anyone shed any light on this??

[johnl320]

I had the same fault a few years ago on my 320 and it was the spring loaded brush that contacts the the ring on the back of the steering wheel it looked okay but it had a feed going into it but nothing coming out the other end, i hope this helps ,
john

[E30Adam]

Did you just change the bush John? Is there any way I can test it with a multimeter?

[Richy325iTouring]

Its the carbon pin (horn contact under the wheel on the colum)
you have to drill the rivits of the old one out and replace with small bolts.

Part number for the pin is BM32.33.1.350.750

Cost Ԛ£3.41 + VAT comes to Ԛ£4.01

[E30Adam]

Its the carbon pin (horn contact under the wheel on the colum)
you have to drill the rivits of the old one out and replace with small bolts.

Part number for the pin is BM32.33.1.350.750

Cost Ԛ£3.41 + VAT comes to Ԛ£4.01

Top man, cheers fella!

[ian332isport]

Adam,

I'll sort you out with a proper circuit diagram tomorrow, but from memory, it's something like this.

When you press the horn button, it grounds one side of the horn relay coil. The other side of the coil will have an ignition controlled live (possibly fused).

You first need to check this half of the circuit is operating. Get Becky to parp the horn, and see if the relay clicks. If it does, then this side of the circuit is okay, and the problem is between the relay and the horn. If the relay does not click, then you need to investigate that side of the circuit.

I'll be in touch tomorrow.

Cheers,

Ian.

[E30Adam]

Ian,

I'm pretty sure that whilt fiddling with it today there were no clicks from the relay at all. I got my mum to press the horn and didn't rear anything from the relay. Is it quite a loud click?? I will double check tomorrow though.

Electrics really aren't my speciality.

[Brianmoooore]

The horns themselves aren't that reliable on the touring's. I've had to change several over the years, but if both horns were working before, and not just one of them, and now none, then it is very unlikely they've both failed at the same time, unless you've been through deep water recently.
If the relay (in the fusebox) doesn't click, then it may be the carbon button as the previous posters have suggested.
Another horn problem I've had on more than one E30, normally causing intermittent horn rather than total failure, is failure of the metal steering column shaft ( the middle part that turns with the steering wheel ) to earth to the body of the car through the column bearing on the bulkhead. Cure is to squirt switch cleaner into the bearing from the engine compartment.

[Davenotouring]

Why are Touring horns less reliable than saloon?

Not doubting it's true, just curious.

I have a problem with the horn on mine, which has recently developed, and got worse.

In the morning, the horn doesn't work, it slowly gets better and lets out a little noise intermittently, after a few minutes, it works normally!

[E30Adam]

Both horns seem to be inoperative. I've never even tried them since I've had the car so don't know if they've ever worked. It's only now come MOT time that I've found out.

I think I'll change the carbon switch and bearing and see if that does the trick. Doesn't break the bank.

[Brianmoooore]

Touring horns are less reliable because they live behind and above the foglights where they collect crud from the road. Most, (but not all), of the saloons I've come across have the horn mounted on the bonnet slam panel.

[E30Adam]

I think it depends if the model came with dual horns, the dual ones seem to come fitted above the fogs but the single horns seem to be located behind the kidley grille.

[ian332isport]

Ian,

I'm pretty sure that whilt fiddling with it today there were no clicks from the relay at all. I got my mum to press the horn and didn't rear anything from the relay. Is it quite a loud click?? I will double check tomorrow though.

Electrics really aren't my speciality.

Adam,

I would normally expect to hear a reasonably solid click from the relay without sticking your ear right up close.

I have just sent some info and the wiring diagram to your Zone e-mail.

Cheers,

Ian.

[mrLEE30]

have your mum turn on the headlights on and off and stand near to the fusebox, (with ignition on) that click will be the light circuit relay and should give you a rough idea what sort of click you are looking for!!

my convertable horn is behind the foglights if any one interested!!!
mr lee

[E30Adam]

Its the carbon pin (horn contact under the wheel on the colum)
you have to drill the rivits of the old one out and replace with small bolts.

Part number for the pin is BM32.33.1.350.750

Cost Ԛ£3.41 + VAT comes to Ԛ£4.01

I think it's going to need re-wiring but I'm going to replace the carbon pin anyway. Do you know if the new pins come with the bolts you need to fit it.

Also, what's this collar people are on about, I might order that as well if anyones got a part number. I can see a metal colar that just sits on the shaft under the steering wheel... is this the one?

[SVBMW]

dave touring wrore

In the morning, the horn doesn't work, it slowly gets better and lets out a little noise intermittently, after a few minutes, it works normally!

My Old Man taught me to once in a while, wait until you're out and about in the country and nobody about, drive with your hand on the horn for half a mile or so.

They don't get used that often and this shakes them into life!!!

[Richy325iTouring]

I had small bolts here but didnt come ith the pin

[Karan]

i had tyhis prob with mine but just fitted a twin tone airhorn from halfrauds for 15quid i think.