Possible sort circuit.

[Classiccars]

Checked the lights and noticed one indicator was not flashing but the sidelight under it was.So removed and both wires looked to be attached but there is an odd black I think wire loose.Wondering if this is a loose earth causing the strange lights .Tried wrapping it around the screw to earth but just the same.Any ideas please.

[svenedin]

This is the late type combined sidelight and indicator light mounted on the front wing? Lucas L632?

I don't know what you say you removed. If you removed the lamp holder base there is no black wire. The lights are earthed by the base mounting bolts. There is only a red and a green wire.

Stephen

IMG_1492.jpeg (1.12 MiB) Viewed 8427 times

[Classiccars]

Thank you yes there are two bulbs the I dictator above the sidelight.It is possible the black wire is for something else.May need to get someone to look at it thanks.

[ManyMinors]

From your symptoms I'd say you definitely have no earth on that light - which is possibly why somebody has added the black wire. If you have no earth, the currect will try to find a return which is why the sidelamp is flashing. Normally, as Stephen suggests, the earth is created through the fixing screws but that has obviously failed on your car. Take the screws out and clean the surrounding metal back to bare steel OR add an earth cable to the light(s) which is what I've done to my car.

[svenedin]

Yes agreed. When you turn on the indicator the electricity is trying to return to earth via the sidelight wire.

You need to undo the 2x mounting screws, spring washers and nuts (2BA x 1") and then clean up the area on the baseplate where the screw heads make contact and the wing where the nuts and washers make contact. There is a gasket between the lamp base and the wing. This may disintegrate when you take things apart. The fixings and the gasket are available from ESM. Incidentally, there should also be 2 gaskets inside the light unit. A foam ring and a thin clear plastic slip ring.

Stephen

[geoberni]

Strange things happening with Indicators/side lights/brake lights are always either an earth fault, i.e. the earth that should be there isn't, so the electricity finds an alternative route, OR in the case of rear lamps it can be a bulb fault in the combined brake/tail lamp.

Clearly in this case, it's not the latter, so it is an earth problem.

Stephen has a car with the latter style front lamp assembly, so he has practical knowledge of the installation.

But what I will say is that according to the wiring diagrams, while the Front Indicators are earthed via the Casing securing screws, the Front Indicators are earthed via black earth cable.

Based on Stephen's example, I'll say the diagram is an error, but this is definitely an earth issue.
I would have expected both to flash if the indicator was earthing via the sidelight circuit, but weird poop happens when electricity looses the intended earth connection.

27 & 38 are front indicators, note no B to indicate a direct earth via casing.
45 & 46 are the front marker lights, having a B to indicate it has a black cable. Almost certainly an error and not the first time I've found an error on the wiring diagrams.
.

Indicator issue.JPG (54.03 KiB) Viewed 8296 times

[svenedin]

I have provided inaccurate information. Apologies.

I have just had a look (photos are difficult to take). There is a black earth wire attached to a ring terminal around one of the lamp base fixing screws. This black earth wire then goes through the wing and earths via a bullet connector to the earthing point on the front of the inner wing.

Stephen

IMG_1493.jpeg (1.93 MiB) Viewed 8292 times

[Classiccars]

Thanks all.i will give it a go in the near future.May get lucky.

[oliver90owner]

I would go with geobernie.

The flasher bulb is 18W while the side light bulb is 5W.

Current being earthed from the flasher through the sidelight bulb would be sufficient to illuminate the 5W bulb but insufficient to appreciably heat the 18W buld to the point where it would become incandescent

My expectation is that, while the sidelight is illuminated, the bulb will not be quite as bright as during the normal sidelight operation.

[Classiccars]

Thank you.I will have a ho and if no luck will get it sorted .

[mike1864]

A picture paints a thousand words.
This rough sketch shows where and how the current seeks a "wrong" path to chassis.
The three bulbs have to divvy up the 12 volts between them; hence are dim.
And when the brake switch closes too, it applies 12V to the negative end of the dodgy indicator. With zero volts across it, it goes out.

[svenedin]

A picture paints a thousand words.
This rough sketch shows where and how the current seeks a "wrong" path to chassis.
The three bulbs have to divvy up the 12 volts between them; hence are dim.
And when the brake switch closes too, it applies 12V to the negative end of the dodgy indicator. With zero volts across it, it goes out.

These are font indicator/sidelights. Only two bulbs.

Stephen

[mike1864]

lost earth photo.JPG (1.06 MiB) Viewed 7013 times

My last post wouldn't let me load the intended picture.
Here it is now (but perhaps rotated 90 degrees)?
It shows a back door circuit through the brake bulbs, but the same principle applies with sidelights.
So there are in fact three bulbs involved; it's just that one of them is on the other side of the car; but connected to the "faulty" cluster.

[Classiccars]

Much obliged.

[mike1864]

I should add that this back door path won't apply if you've got LEDs.
This path depends on the adjacent brake (or tail/side) bulb not caring which way the electric flows through it to make all three light up (weakly!).
The D in LED stands of course for diode, ie it blocks current in the undesired direction.
The bottom line is that if wrong lights are dimly coming on, it's due to a poor earth!

[Classiccars]

No never led for me ta.Will try to sort this weekend.