Windtone horn……. Again

[MsRose]

Sorry all. I’m becoming a pain with this flipping horn.

I went to bench test today and there’s a really strong spark when I connect the horn to my battery.

The contact appears closed to me. Would it be anything to do with that? I don’t want to burn the coil out

[svenedin]

You’ll burn the coil out if you leave it connected to the battery and the contacts are closed and not opening and closing. The coil isn’t designed to have a constant current flowing through it.

Is it working at all having cleaned the points?

If it is too much at the moment pick up a working one at an auto jumble and come back to your one later on. You can even buy a modern reproduction or make do with a £10 plastic one for now.

Stephen

[geoberni]

A closed contact is like putting a short on a battery, it pulls loads of power.
it's similar to the fuel pump, the coil moves an armature and that makes and breaks the circuit.
See this video, it explains it quite well.
https://youtu.be/WEpS3D9WQb8?t=78

[MsRose]

A closed contact is like putting a short on a battery, it pulls loads of power.
it's similar to the fuel pump, the coil moves an armature and that makes and breaks the circuit.
See this video, it explains it quite well.
https://youtu.be/WEpS3D9WQb8?t=78

This is great, thank you. I came across this video some days ago and then just couldn’t find it at all!

I’ve re cleaned everything and made sure the points are lubricated. I’ve got someone who’s going to test the coil etc next week as I’ve not used a multi meter before. I hate things getting the better of me!

[MsRose]

Thank you all so much for your help. The horn is working.

Not sure I can post the video of it on here, but please do take a look if you're interested on Muriel's Facebook page https://www.facebook.com/groups/1309792820116561

[svenedin]

Oh yes. Working rather well. Great sound! Well done.

[MsRose]

Oh yes. Working rather well. Great sound! Well done.

I'm so pleased!

[svenedin]

Glad you're pleased. I fixed the horn on my car. I was really upset it stopped working. I used a cheapo modern horn for a while (because a working horn is a legal requirement) but it wasn't the same at all. Then I managed to fix the original horn which on the later 9H type means drilling out rivets to open the case. Then my car got his voice back and a very loud period sounding voice it is too!

Stephen

[MsRose]

Glad you're pleased. I fixed the horn on my car. I was really upset it stopped working. I used a cheapo modern horn for a while (because a working horn is a legal requirement) but it wasn't the same at all. Then I managed to fix the original horn which on the later 9H type means drilling out rivets to open the case. Then my car got his voice back and a very loud period sounding voice it is too!

Stephen

A few people told me just to replace the horn, but Muriel has so much original stuff on her that I'd hate to deviate. I was determined to save it. I've tried to save the fuel pump but the cylinder in the middle that runs up the body of the pump is stuck solid. For me, it's about trying to keep as much of her alive as possible.

[svenedin]

That's marvellous to hear. If it is an SU AUA66 fuel pump there is a high chance it can be fully restored. The only fault that condemns a fuel pump is if the coil (which is inside the cylindrical metal housing) has burnt out. Replacing it is beyond most DIY and not really worth doing. You can buy a full pump overhaul kit from Burlen Fuel systems but do note that the overhaul kits are slightly different for pre 1985 and post 1985 pumps. Overhaul is straightforward except that the points need to be set up carefully with feeler gauges or the pump either won't work at all or will work badly. I think you are describing the diaphragm being stuck. It unscrews from the points at the top (the end of the operating rod is threaded). A rebuild kit comes with instructions but the SU workshop Manual is far better and covers carburettors as well: https://sucarb.co.uk/catalogues-manuals ... anual.html


Also see here: viewtopic.php?t=57395

Stephen

[geoberni]

I've tried to save the fuel pump but the cylinder in the middle that runs up the body of the pump is stuck solid. For me, it's about trying to keep as much of her alive as possible.

Cylinder in the middle?

That's confused me. What 'Cylinder'?
The Coil is permanently fitted to the housing.
I've only ever seen one image of Coils not fitted in housings and I suspect they may have been cut open...
The Diaphragm connects by it's operating rod to the Rocker Assy in the top.
The Diaphragm requires unscrewing from the Rocker Assy in order to dismantle the Pump.

SU Pump breakdown.JPG (80.2 KiB) Viewed 4733 times