New "Lucas" Indicator Assembly Problems

[svenedin]

A while ago, maybe 2 years, I had to replace my (presumably original) indicator assembly. I bought a new assembly from ESM that was branded "Lucas" and it is marked on the metal "England". This replacement assembly developed problems where it worked intermittently and I complained to ESM. They replaced it and so I finally got round to it and installed the replacement about 6 weeks ago. This too developed a problem whereby in one direction the indicators work normally but in the other direction the "latching" mechanism that holds the arm in the left or right position is so insecure that the electrical connection to the indicator bulbs on the car is intermittent. It is possible (but dangerous while driving) to hold the indicator stalk down and the indicators flash but if I don't do that the indicators might work or might not. Obviously this is rather dangerous and the car would fail an MoT test. To think I am indicating but I am not. It so happens that it is especially dangerous because the fault is in the indicating right direction which tends to hide the tell-tale lamp under the spoke of the steering wheel.

Reluctantly, I took everything apart again yesterday and I determined that the problem is with the latching mechanism. As I am taking the car to France next week I cannot have a fault like this. Even more reluctantly, I installed a new old stock Lucas indicator assembly (a rather rare thing) that I had collected years ago but had only intended to fit once the car was completely restored. Just comparing the new and old assemblies by eye does not show much. They look more or less completely identical but as soon as the action of the two is compared it is apparent that the new one feels wobbly and insecure whereas the old one locks perfectly in place when the stalk is moved left or right. Of course, the new old stock assembly worked perfectly first time.

A few weeks ago I was down at the Morris Minor Workshop in East Sussex having a moan about the quality of new parts. In this case the moan was about brake light switches but the mechanics said as an aside that they are having terrible trouble with indicator assemblies.

So what is the reason for this post? Firstly, don't replace your tatty old indicator assembly unless you absolutely must. If the black plastic is snapped where the bulb goes in this can be replaced with a part from the Dorset branch of MMOC. Secondly, I realise that most people will not have new old stock parts to fall back on and so I am wondering whether with some fettling, the new switches can be adjusted to work reliably. I think some careful bends might make the latching mechanism work properly. This I will have to try when I have the time.

Lastly, why is this happening? This is pure speculation. I think this particular part is pretty well made but I hypothesise that the problem occurs at assembly. Years ago the workers on the assembly line would be making these assemblies day in, day out. A tweak here, a bend there, test, next one. This is where things are going wrong. The parts are leaving the factory just about working but not reliably.

Pictures to follow.


Stephen

[svenedin]

Unlocked position. Stalk in mid position, not indicating left or right. Note the circular copper electrical contact. Note also the use of a green wire travelling up inside the stalk to the tell-tale bulb. The original uses a much thinner white and black wire. The green wire has been chafing and is too thick. It catches the self-cancelling cams.

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Indicating right position, stalk down. Faulty. Part A not latching into Part B. No electrical contact, no indicators flashing

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Manually pushing part A onto Part B. Securely latched, electrical connection made, indicators flash.

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[geoberni]

I agree, that green cable is far to thick, probably both in the wire gauge itself and the insulation around it.
It should be thin 'equipment wire', not the same stuff as used to wire up the car itself!
Have they brought a return cable down the stalk as well, or is the lamp earthed via the stalk?
Earthing via the stalk would be very poor practice due to the moving surfaces.

[Mervin]

A couple of pictures showing the black/white warning light wire. and it's connection to the larger light green wire underneath the switch mechanism which is the feed from "P" on the flasher unit. At the big blob of solder.

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[svenedin]

I agree, that green cable is far to thick, probably both in the wire gauge itself and the insulation around it.
It should be thin 'equipment wire', not the same stuff as used to wire up the car itself!
Have they brought a return cable down the stalk as well, or is the lamp earthed via the stalk?
Earthing via the stalk would be very poor practice due to the moving surfaces.

On an original unit the light green wire from "P" terminal on the flasher can becomes a much thinner black and white wire at a solder joint, then goes up the inside of the indicator stalk. The black and white wire is one wire not a twisted pair so the earth for the tell-tale (pilot) bulb must be via the metal of the stalk in both old and new assemblies.

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IMG_1869.jpeg (2.1 MiB) Viewed 3924 times

[svenedin]

A couple of pictures showing the black/white warning light wire. and it's connection to the larger light green wire underneath the switch mechanism which is the feed from "P" on the flasher unit. At the big blob of solder.switch 1.jpgswitch 2.jpg

Thanks. Yes! I have just added pictures showing the same.

Stephen

[Mervin]

" tell-tale (pilot) bulb must be via the metal of the stalk in both old and new assemblies. " That would appear to be the case Stephen. The wiring diagram I have just shows a single wire to the lamp, then to earth.
That black/white twisty colour coding looks much fancier that inline colouring.

[geoberni]

On an original unit the light green wire from "P" terminal on the flasher can becomes a much thinner black and white wire at a solder joint, then goes up the inside of the indicator stalk. The black and white wire is one wire not a twisted pair so the earth for the tell-tale (pilot) bulb must be via the metal of the stalk in both old and new assemblies.

Surprising they relied on that; they must have decided it was enough continuity due to rivets etc.