Morris Minor Owners Club

I just replaced the indicator stalk with a new one. Unfortunately this slip ring seems to thin: this image is after I already pushed in the horn brush quite a lot.


The old stalk fix was to bend it such that the edge not flat plane of the brush contacted:


What fix should I do going forward:
1. Same as old fix (but might choose too much wear)?
2. Try and bend it even more to get it closer to the slip ring but flat? Might take away any springiness?
3. Add copper tape to widen slip ring?
4. Find another slip ring (or even new steering column if it is not a Minor one)?

Also, I note that the indicator stalk fits only one position on the plastic tubing. The self-cancelling did not work previously. Is it ok for the plastic tubing to be moved further out than it was to line up, and is it the very thin triangle teeth which should line up or a more substantial part of the indicator assembly?

Finally, the new indicator has a longer length of exposed wires. Is it ok to allow the wires to go through the bracket individually or should I slide and retape it?


Many thanks!

So in the end I tried bending it like before and then using 180 grit to get the brush into a better shape. As the paper isn't totally thin, the curve on the brush is higher radius than the ring but hopefully it allows more contact along the axial direction of the slip ring. In addition, I'll smear some highly conductive grease on in the hope that it helps.

I would say the problem isn't the Slip Ring but the quality of the replacement switch.
It's difficult to tell how bad the problem is from your photos, but here's what I'd do if it was too poor a contact.
My solution would take a little bit of work but I'd get a small piece of copper pipe, cut a section of it to get a curved piece about the same size as that contact and solder it onto the contact face.
Making sure I had de-burred it, rounded all the edges and so on.

Of course that all depends on having suitable soldering equipment, that you can heat up that contact area without damaging the rest of the assembly.

The previous second hand one had to be bent this way, which make me suspect it was actually a narrow slip ring but maybe they all have the same problem in terms of the brush not hitting the slip ring?

Ah yes sounds good but I guess you'd want to make sure the pipe has spot on the correct diameter or it would be no better than the current solution. If that fails to hold up, I could try this.

nwxh wrote: ↑Tue Jul 13, 2021 12:14 pm The previous second hand one had to be bent this way, which make me suspect it was actually a narrow slip ring but maybe they all have the same problem in terms of the brush not hitting the slip ring?

Ah yes sounds good but I guess you'd want to make sure the pipe has spot on the correct diameter or it would be no better than the current solution. If that fails to hold up, I could try this.

I've got no 1st hand experience of this switch since my SII doesn't have such fancy devices. But from your photo, it looks as though there are 2 issues, firstly the contact is flat, and secondly it's too far away.
Designing it with such a large flat area seems pointless unless it's being used.

Even this supposedly Genuine Lucas one I found on ebay at £125 seems to have the same issue. Assuming 2 x 21 W lamps and a tell tale lamp, you're looking at a little over 3 Amp through that contact. I'd have thought a better surface area was required.

Perhaps someone with this type of stalk can contribute?

As berni suggests, the switch seems to be a poorly made reproduction part. The contact should not have to be fiddled with. His calculations regarding current are incorrect however as the contact has nothing to do with the indicators. It is there to provide an earth for the horn operation

ManyMinors wrote: ↑Tue Jul 13, 2021 1:20 pm As berni suggests, the switch seems to be a poorly made reproduction part. The contact should not have to be fiddled with. His calculations regarding current are incorrect however as the contact has nothing to do with the indicators. It is there to provide an earth for the horn operation

Dohh!
I told you it needed some input from someone with experience of this particular installation.
I should have thought about it, no need for an earth at that end of the circuit for the indicators.
I'm only used to the slip ring on my SII which had a completely different arrangement, which makes me wonder why such a large contact on the latter switches? Perhaps that's what threw me off track.
it only needs a small contact, just look at the relative contact area on mine, a square mm at best.

I'd be tempted to just put a small blob (technical term that) of solder on the contact face, but what you've done is probably fine. I wouldn't go putting conductive grease on there as it'll just attract dust/dirt to the surface.

Ah right, perhaps it is just poor quality. This is a new batch, them having been "sold out" for some time, so looks like another failed attempt. The other complaint I have is that the wire to the horn has a gap in insulation just before it is soldered.

Thanks for the suggestion about avoiding dust. In that case, I'll just clean it up and leave it. I think the current could be over 10 amps. Perhaps I'll dare use an ammeter to get a reading.

As for the purpose, the ring and contact connects (or should connect) to the little pin at the front of the steering wheel. The push button then earths this via the steering rack to sound the horn. By default it is not earthed but is on the earth not battery side of the horn.

Even this supposedly Genuine Lucas one I found on ebay at £125 seems to have the same issue.

I think that's the one ESM are currently selling, which I have, for much less than that price.

I've checked my horn in the past and it is about 3.9 - 4.0 Amp, obviously it would depend what horn you have.
Mine's the original single one.
I'm lucky, I have a Clamp Ammeter with a peak hold selector, so a quick blip of the horn with the clamp around the actual steering column. No annoying the neighbours while reading the meter.

I got 2.4A just now but didn't hold it too long.

Edit: I have since got it all back together and done a test drive. The horn and self-cancelling are working. This is my first time with the self-cancelling indicators working so I need to drop my habit of cancelling myself with it.

So all in all, the new offering is not bad. The only other snag seemed to be that the bracket on the left side appears to bend quite a bit each side of the screw once tightened but then my column surround might not be the co