Horn not working

[monty]

Driving yesterday the horn suddenly only worked intermittently & now today it does not work at all. I have taken the horn push out from the Motalita wheel along with the ‘pencil’ which is a little worn on the soldered end but not excessively. With the steering wheel off the copper ring appears pretty clean. There is a plastic disc with a cutout (presumably for the ‘pencil’) but it just appears to ‘float’ on top of the copper ring so not sure what that does. The ‘pencil’ is the 2.6 length but it has worked fine for years with the Motalita wheel. 
A bit baffled so any suggestions gratefully received.

[John Morrison]

Monty check horns own in line fuse first then use a screwdriver down the pencil hole to earth against the side.

If that gets to blow the horns your issue is at that end.

 If not you could check that earth continuity wires that bridge the rubber doughnuts in the steering column are still intact 

next wound be a wire directly from the battery to each horn in turn to ensure they are still working 

John

[BlueTR3A-5EKT]

42 minutes ago, John Morrison said:

Monty check horns own in line fuse first then use a screwdriver down the pencil hole to earth against the side.

If that gets to blow the horns your issue is at that end.

 If not you could check that earth continuity wires that bridge the rubber doughnuts in the steering column are still intact 

next wound be a wire directly from the battery to each horn in turn to ensure they are still working 

John

Rack wants to be earthed too.

[monty]

2 hours ago, John Morrison said:

Monty check horns own in line fuse first then use a screwdriver down the pencil hole to earth against the side.

If that gets to blow the horns your issue is at that end.

 If not you could check that earth continuity wires that bridge the rubber doughnuts in the steering column are still intact 

next wound be a wire directly from the battery to each horn in turn to ensure they are still working 

John

Thanks for that John. What is that plastic disc & what does it do apart from possibly preventing a good contact between the copper ring & the pencil push?

[John Morrison]

Monty 

don' know about the plastic disc, I haven't got one - perhaps something to do with the 

non Triumph boss?

John.

[BlueTR3A-5EKT]

Is the pencil end actually in contact with the slip ring?   Or is the plastic disc getting in the way?   

[monty]

2 hours ago, BlueTR3A-5EKT said:

Is the pencil end actually in contact with the slip ring?   Or is the plastic disc getting in the way?   

That was my thinking & have ordered the much better pencil from Motalita.

[keith1948]

Hello Monty

I'm thinking that the plastic disc should be attached to the underside of the steering wheel boss not 'floating' as you describe. The pencil needs to contact the copper ring which has a wire soldered to it. Have a look at the wiring diagram and then check all connections. I had a loose spade connection on one of the horns recently so only one horn was working. It should be fairly easy to find the fault now it doesn't work at all. Easier than trying to find an intermittent fault.

I am also wondering how you noticed the horn working intermittently. Do you use it a lot? I rarely use the horn. Only time I had a problem on the road was a few years ago in the lakes when the wire that should have been soldered to the copper ring was shorting out causing the horn to come on every time I braked.

Keith

[monty]

Still trying to find this fault! Just been checking the relay & using a test led light I have power @ terminals C2 & W1 but nothing on terminal C1 that connects to the actual horns. My electrical knowledge is basic so can anybody tell me if this is correct or should C1 also be live. Could this be the fault? Apparently this relay is unavailable @ Moss so what are the alternatives if this is faulty?

[RobH]

C1 will have no voltage on it until the relay operates.  Internally that relay has a link from C2 ( power in ) to the top of the relay coil (which would be W2 if it had been connected to a separate terminal).   Earthing W1 should operate the relay and sound the horn.  If that doesn't happen the relay is probably duff.   If you link C1 to C2 it will power the horns directly to check they work. 

If you can't get the right relay, you could use an overdrive relay by linking both C2 and W2 to +12v . 

However, I see the O/D relay is incredibly expensive so you could also use a modern relay at about one tenth the cost and connected like this:

+12v to pins 86 and 30, (purple wire)

Horn push to pin 85 ( purple/black)

pin 87 to horns. (purple/yellow)

 

Edited May 26, 2023 by RobH

[monty]

1 hour ago, RobH said:

C1 will have no voltage on it until the relay operates.  Internally that relay has a link from C2 ( power in ) to the top of the relay coil (which would be W2 if it had been connected to a separate terminal).   Earthing W1 should operate the relay and sound the horn.  If that doesn't happen the relay is probably duff.   If you link C1 to C2 it will power the horns directly to check they work. 

If you can't get the right relay, you could use an overdrive relay by linking both C2 and W2 to +12v . 

However, I see the O/D relay is incredibly expensive so you could also use a modern relay at about one tenth the cost and connected like this:

+12v to pins 86 and 30, (purple wire)

Horn push to pin 85 ( purple/black)

pin 87 to horns. (purple/yellow)

 

Many thanks Rob. The horns & relay work after doing what you suggested. Where to go next?

[RobH]

If the relay is working when you earth W1, the only thing that can be at fault is the link to earth from pin W1 via the horn push.  You could check the connection up to the copper ring for the 'pencil' by earthing the ring with a wire. If the horns work then, it must be the pencil not making contact, or the steering column not being earthed. 

If the horns don't sound when you earth the ring there must be a bad connection in the purple/black wire  from the relay. 

[monty]

5 minutes ago, RobH said:

If the relay is working when you earth W1, the only thing that can be at fault is the link to earth from pin W1 via the horn push.  You could check the connection up to the copper ring for the 'pencil' by earthing the ring with a wire. If the horns work then, it must be the pencil not making contact, or the steering column not being earthed. 

If the horns don't sound when you earth the ring there must be a bad connection in the purple/black wire  from the relay. 

I am suspecting the column earthing now but the earth wires look ok but difficult due to location to be sure. When this problem started I replaced the standard pencil with a Motalita connection so will be surprised if that is at fault. Will try & check the copper ring later.

Thanks again.

[monty]

Hi again Rob. No joy when earthing the ring & no noise from the horns! Appears to be a good connection with the wire to the back of the ring. Is there an easy way to check the earth wires are good on the steering column? 

[keith1948]

Hi Monty

Saw this earth wire "fix" on a TR a while ago. Wrap a bit of copper wire around the metal bit of the column above the top rubber connector in the engine bay and connect it to earth. If horns work when you press the horn push then the fault is with the earth connectors on either or both of the rubber connections or further down by the rack. You could also use a multimeter to check continuity of earth across the rubber connectors. There should be a wire (part number 130581) that bridges the rubber connectors.

Keith

[RobH]

Where did you connect the earthy end of the wire for that test Monty?  If it was to a solid bit of metalwork  - other than the column - the horns should work.   If you did that it could be that the wire from the relay is open circuit. There is an in-line  bullet connector joint which might be iffy. 

As Keith says,  there should be jumper wires across the joints in the column which give continuity.   If you have a small 12v bulb with wires,  you could connect one end to 12v and touch the other end to the column. If the earth is good the bulb will light. 

 

 

Edited May 26, 2023 by RobH

[monty]

Many thanks to Rob& Keith for all your suggestions. The copper wire fix has appeared to work! Tried it a couple of times yesterday & the horn worked 2 out of about 3 times so still a small earthing problem but at least we know where we are! Until I can replace the correct 130581 wires is it safe to leave the copper wire in place to say get through MOT?

[Lebro]

As long as the wire is stranded - i.e. flexible.  a solid copper wire could soon fracture.

(But I'm sure you knew that !)

Bob

[keith1948]

2 hours ago, monty said:

Many thanks to Rob& Keith for all your suggestions. The copper wire fix has appeared to work! Tried it a couple of times yesterday & the horn worked 2 out of about 3 times so still a small earthing problem but at least we know where we are! Until I can replace the correct 130581 wires is it safe to leave the copper wire in place to say get through MOT?

Hello Monty

As Bob has said, if you plan to keep this for MOT then a stranded wire might be better. The car I saw this 'fix" on seemed to have it as a more permanent fixture but you would do better to now see where the fault lies. Temporarily fix a wire across the top rubber connector and try the horn. If it works then that is where fault lies. If it doesn't then bridge across lower rubber connector. It should now work. If it still doesn't work then there should be an earth wire from the top of the 'box' where the column meets the rack. This wire on mine connects from the top of the 'box' (under the hex bolt) to the rear bolt of the rack clamp. In other words earth route is as follows - top part of column (where you have just fitted copper wire), wire connector across top rubber connector, next section of column, wire connector over lower rubber connector, lower bit of column to rack, earth wire from top of rack to front chassis member.

Why Triumph chose this method has puzzled me but must have been some reason or an afterthought.

As a temporary fix if it is just one of the earth wire connectors at fault then use a couple of jubilee clips above and below rubber connector and run an earth wire between them. Just make sure the clips don't catch on anything as the steering column rotates. 

Keith