1973 Fulvia Coupe Horn

[KeithWade]

Probably going over old ground here but just can't seem to get the horn operating. Someone once said that the more puzzling a problem is the more simple the solution is likely to be!

 I've carried out all the usual tests and checks for operation and continuity and the various components seem fine.

Just wondered if anyone can point me in the likely location of the earthing point from the horn button (steering column somewhere?) ? The black wire I believe......

I haven't quite pulled all of my hair out yet!!

[lancialulu]

Have a look at the horn relay located on the upper front inner wing. Connector could be dirty or relay contacts need cleaning. Lancia Relay tin can can be easily opened up....

[KeithWade]

OK I will do that...thanks.

Would still love to find the earthing point for the horn though if anyone has any suggestions........?

[Brian Long]

Have you checked whether the small carbon brush is contacting the brass ring on the back of the steering wheel boss?
Brian

[KeithWade]

Hi Brian

Yes.. in fact I fitted a new (Omicron supplied) one and spring and there is definitely contact. In fact you can hear it slightly as you turn the wheel........

[chriswgawne]

I am not sure whether your horn contact on the steering box is the same as that on a S1 but it might be worth checking the contacts down there with a testmeter.
Chris 

[KeithWade]

Oh OK Chris..the steering box you say? Is this an earth then?

[lancialulu]

I am not sure whether your horn contact on the steering box is the same as that on a S1 but it might be worth checking the contacts down there with a testmeter.
Chris 

S1 is very different to S2 and there is a black wire from the back of the earthing plate in the steering wheel that goes to a 4 way junction block and then on to the horn relay. It should be easy to localy earth the “1” terminal on the horn relay to see if the relay activates (I think the ignition needs to be on). The relay is supplied “2” by fuse 9 for the horns and “3” on the relay is the live side of the relay coil (fuse 7 always live).

[KeithWade]

Ok thanks for the suggestion.

I will try this and report back.......

[KeithWade]

Well..this puzzle continues. The problem is definitely earth related at the horn push end it seems. The horn operates successfully with the ignition on if I run a test wire from the earth terminal on the horn relay to a separate earth in the front wing. It also operates successfully with ignition on if I run the wire from the earth terminal on the relay to the centre steering wheel spline so the steering column is earthed it would seem. So the issue is clearly with 'upstream' earth wiring from the relay to the brass horn contact or with the horn operating button gear. I have replaced the earth wire between the contact ring and the orange terminal block as when I checked this the copper wire was badly corroded at the contact ring end. Thought this was the issue but still no joy sadly.

[fay66]

Well..this puzzle continues. The problem is definitely earth related at the horn push end it seems. The horn operates successfully with the ignition on if I run a test wire from the earth terminal on the horn relay to a separate earth in the front wing. It also operates successfully with ignition on if I run the wire from the earth terminal on the relay to the centre steering wheel spline so the steering column is earthed it would seem. So the issue is clearly with 'upstream' earth wiring from the relay to the brass horn contact or with the horn operating button gear. I have replaced the earth wire between the contact ring and the orange terminal block as when I checked this the copper wire was badly corroded at the contact ring end. Thought this was the issue but still no joy sadly.

What about the horn contact and slip ring at the bottom of the steering column and the flexible coupling?
Brian
8227 

[KeithWade]

Ahh.... puzzle solved Brian! The actual fault causing the failure was the corroded connection. The continuing puzzle was down to a coating of clear laquer. While trying to address this issue I swopped the original steering wheel for a more substantial Flavia one but had to clean off some old black paint from the spokes. After getting it to bare metal I decided to laquer it and must have also sprayed the centre of the wheel without thinking. This has caused insulation between the bare metal and the brass horn spring hence no ground! Happy days......Thanks for your suggestions though and continued interest.

[fay66]

Ahh.... puzzle solved Brian! The actual fault causing the failure was the corroded connection. The continuing puzzle was down to a coating of clear laquer. While trying to address this issue I swopped the original steering wheel for a more substantial Flavia one but had to clean off some old black paint from the spokes. After getting it to bare metal I decided to laquer it and must have also sprayed the centre of the wheel without thinking. This has caused insulation between the bare metal and the brass horn spring hence no ground! Happy days......Thanks for your suggestions though and continued interest.

Your welcome Kevin, pleased you've sorted the problem, keep up the good work.
Brian
8227