Horn Button ....

[Laird Scooby]

Thanks Bob - useful info there. I sometimes think of fitting the steering wheel with the two horn buttons, currently got the later sort with the horn pad/steering wheel centre pad.

Salmon that tastes like carp? Something fishy going on!

[bob12]

Originally Posted by Laird Scooby

Thanks Bob - useful info there. I sometimes think of fitting the steering wheel with the two horn buttons, currently got the later sort with the horn pad/steering wheel centre pad.

Salmon that tastes like carp? Something fishy going on!

Had to reply ... can't stand the 2 horn buttons and never have done since the car was new!

Usually you need to use the horn when turning the wheel not when going straight ahead. When the wheel is on the turn you never quite know where the either of the buttons are!!

This is one of my biggest pet hates of my 745. Give me a horn button in the middle or on a stalk; at least you know where it is when you need to use it.

[Laird Scooby]

Originally Posted by bob12

Had to reply ... can't stand the 2 horn buttons and never have done since the car was new!

What you need is one like this Bob :

https://www.ebay.co.uk/itm/volvo-740...kAAOSw9mpZ63KU

Or one like mine, similar design to yours but with the centre pad also serving duty as the horn pad and no separate buttons.

[Ian21401]

940, 1992.
Been having problems with horns not behaving as they should so tested them individually and found that they were finished. Obtained a couple of decent condition ones from a local breaker. Tested them singly then connected together then fitted them but not much better so problem elsewhere.
Horn buttons are on the steering wheel spokes and neither working as they should so decided problem was elsewhere.
Previous experience with Triumph Herald and Morris Marina with horn buttons in centre of steering wheel is that there is a spring loaded contact brush fitted within the steering wheel centre which "brushes" on a circular contact beneath the steering wheel centre and this becomes dirty over time, so
Removed the buttons,the surround and the brass/copper sprung plate from the wheel spokes as described elsewhere.
Removed the steering wheel central pad (It simply pulls out of the steering wheel rubber ) There is a single core electrical connection which is attached to a sprung device which passes through the steering wheel boss.
Remove steering wheel which exposes the "contact ring" which surrounds the steering column.
The sprung device is connected to a spade terminal in the steering wheel centre and has a carbon type brush on the end which contacts the contact ring. Both it and the contact ring were very dirty so they were cleaned up with fine paper.
Having done all this I wished to satisfy myself as to how electrical contact was made.
The contact ring is live with ignition on.
The sprung brush is connected to a terminal which connects within the steering wheel to the centre contact below the horn push button in the wheel spoke so this contact is also ignition live.
The metal plate surrounding that central contact (but electrically insulated from it ) is earthed through the steering wheel to the steering column.
The sprung plate which fits beneath the horn push is in permanent contact with the earth plate but does not contact the central contact until the horn push is depressed.
When the horn push is depressed the sprung plate makes contact with the central contact and earths the live feed so sounding the horns.
Everything cleaned up and now horns work as they should.

[Laird Scooby]

Excellent work Ian!

[bob12]

Sorry I didn't post the minutia of the the track of the positive feed at the wheel to ground Ian but I resolved my problem by just sorting out the horn push button on one side.

It might have saved you some 'digging' if I had explained more!! Glad you got it sorted though.

This, or another thread on 'Hooters', will be updated shortly (eventually) when I have wired up the new extension loom I have made for my two new hooters mounted on vacant studs below the header tank on my 745!! Bob

[Ian21401]

Not a problem Bob. Your info. was a good starting point for me. I would have probably fiddled with it in any case. As neither button was working I suspected that the fault was elsewhere, which it appears to have been as cleaning the contact ring and brush appears to have solved the problem. IIRC the previous experiences I mentioned with the Herald and the Marina, the spring contact and contact ring may have been the earth as the horn fixings were the earth with only one wire to the horn contact, but I may be mistaken. In any case they regularly required cleaning.
Whilst I was “digging” I found the remains of a broken circlip loitering around the steering column. It’s locating groove was obvious but it was not obvious why it needed to be there. I have a replacement on order from classic parts so will update this thread after receiving and refitting the new circlip.

Ian

[940volvoman]

Unless I've missed it there is no clear indication of how to repair the button once the black plastic piece has been removed.

Is it repairable without breaking??

"Removed the buttons,the surround and the brass/copper sprung plate from the wheel spokes as described elsewhere."

Where, I couldn't find it....?

[bob12]

I have a box of horn push bits but they have been swallowed up in the black hole that is my garage!!

However, I have just taken the push to bits on a spare steering wheel. It all comes back to me now after all this time. It is very likely that you will find the copper spring part has shifted in its plastic frame assuming it is that part that is at fault. The copper spring part is pretty strong and it is unlikely it has bent out of shape.

All I had to do was reposition it correctly on to the top and bottom plastic ridges of the horn frame and clip the push back on.

Bob

[940volvoman]

Thank you for taking the time to look into it,Bob,but my brain must be fried.

It would seem to ne,though from your description that it IS possible to remove the copper strip which the first bit to bee seen under the plastic 'beauty' button.

I cant see how, and dont want to break it.

Shaun

PD I hope to be onto refurbishing the clutch slave cylinder soon that we spoke about earlier in the year.....