Bizarre horn problem

Post by **robo** » 30 Aug 2006, 09:34

I've spent ages getting nowhere on this one.

My horn doesn't work, just makes a pathetic crackling noise, but it does work if I put it directly across the battery.

I know that the connection from the fuse box, through the horn, the button and then to ground is good as the voltmeter shows no connection before the button is pressed, and a good connection when the button is pressed. The problem is somewhere between the ignition and the fuse.

I only measure 10v at the fuse box (which is before the horn), so I am assuming some unwanted grounding or poor connection, i tested for this and found a 30ohm resistance to ground (ignition side of fuse box). But, the really strange thing is when I connect the voltmeter from the fuse to ground, the horn works!! why does it tease me this way?

Post by **SplendiferousII** » 30 Aug 2006, 10:55

I have a problem with my horn, but not quite the same syptoms yet I think the source may be the same.

My horn only works periodically and I think at only certain positions with the steering wheel.

There must be a connection either at the top of the steering columb or at the base where the feed (positive voltage) is passed across onto then through the shaft.

This connection is probably dirty.

Post by **robo** » 30 Aug 2006, 11:03

I checked that side of things, the connection through the steering wheel is fine. My problem is somewhere before that.

Post by **kevtherev** » 30 Aug 2006, 12:42

Can you run a test wire from the batt to the fuse..does it work then?
Check that the relevant wiring behind the fuses is in good order and the fuse is well seated, try and track the wire to the power
I'm not sure if the horn is a constant live....anyone?

Post by **robo** » 30 Aug 2006, 13:33

I'll try the test wire when I get home, didn't think of that one, cheers.

the horn is constant live, the button connects it to earth.

It could quite easily be something behind the fuse box, it looks like a birds nest in there, just want to try everything else before I go down that route.

Post by **Mocki** » 30 Aug 2006, 13:49

test with a neg test wire first, it is nearly always the switched connection at fault......

a cheap and easy solution is run a new live to it from the fuse box, and if that dont cure it relay switch it .

Post by **Dan Wood** » 30 Aug 2006, 20:01

SplendiferousII wrote:I have a problem with my horn, but not quite the same syptoms yet I think the source may be the same.

My horn only works periodically and I think at only certain positions with the steering wheel.

There must be a connection either at the top of the steering columb or at the base where the feed (positive voltage) is passed across onto then through the shaft.

This connection is probably dirty.

You can carefully lever out the horn switch from the wheel, and the carefully open up the switch by levering off the top cover.

Inside are springy metal plates. Carefully remove them from the switch body, and you will probably find them all green and furry! Polish them up with some wire wool or similar until you've got shiny metal again. Then reassemble and enjoy the 'parp' !

Only trouble is, if it's like mine you end up with bare metal that rusts again. There is a trace of some original (brass?) plating, on my contacts, but I need to clean them now about once every 6 months or so.

Post by **lhd** » 30 Aug 2006, 23:17

My horn only works periodically and I think at only certain positions with the steering wheel

Had the same problem, turned out to be the spade connector on the join at the steering coupling ( at base of steering column, under steering cowl).
Turned out the spade connector had eased open over time...
Justt crimped it tight and all ok now.......
worth a look................
LHD..................

Post by **robo** » 31 Aug 2006, 08:24

Hey mines a LHD drive too, I did already notice that connector looked a bit dodgy, soldered it on to be sure to be sure.

Anyway I think I have found the root of the problem now, I spent some more time going through all the connections, and I am pretty sure that it is the cable that runs from the horn back to the steering wheel (even though it seemed to be ok the first time i tested it). The horn works when I run a tester cable from the horn to the connection before the steering wheel (still have to press the button so I know the fragile sliding connections and steering column grounds are ok).
I am going to put a new cable across tonight, see if it fixes it.

can't imagine how it broke, perhaps something wore through the cable somewhere.

Post by **kevtherev** » 31 Aug 2006, 10:23

Elves mate..it's well documented

Post by **robo** » 31 Aug 2006, 14:43

woo yay, fixed it, it was the connection between the horn and the button, stuck a new cable in, perfect. I did notice a half eaten burger below the radiator, so perhaps the king of rock and roll did chew through the cable. better go to the shop and get some more traps.

Post by **kevtherev** » 31 Aug 2006, 14:53

No ...no I meant elves

Post by **phil n gayle** » 31 Aug 2006, 16:07

my horn only works in certain positions and was told it's because on the back of the steering wheel there's a metal ring that completes the circuit and this has worn away in some places, could be the same thing

Post by **robo** » 31 Aug 2006, 16:14

yeah i did check the ring, but it wasn't that, fixed it now see my post above.

I would probably have fixed it a lot quicker if I was more methodical about checking connections with the voltmeter.

oh ELVES, right i understand now. (Damn, now how am I going to get rid of this huge man in a silver suit, now he really is dead).

Post by **robo** » 04 Sep 2006, 13:48

Aaarghhh, it has stopped working again, it worked fine for a few days but now it's screwed, better go and find the voltmeter. probably end up doing a relay job. i blame the last guy who owned the van.