wire going to a sender unit that I should not have ?

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miker519
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wire going to a sender unit that I should not have ?

Post by miker519 »

Hello all
I have a little puzzle regarding a green wire with a brown tracer going to what looks like a temperature sensor that I should not have mounted in the r/h side of the cylinder head just below the thermostat housing. Should this wire have gone to the oil filter sensor which has been removed due to a spin on conversion ?
Also the engine has an L before the five digit number which I think may mean low compression so has the head been changed?
The car is a 1965 2 door saloon is there a wiring diagram for this on the club site as all the links that I have tried to follow seem dead.
Thanks for looking MikeR519
simmitc
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Re: wire going to a sender unit that I should not have ?

Post by simmitc »

The filter warning light used green/yellow. Green/brown is usually used for reversing lights (not standard on a Minor) so is likely to have been used by a previous owner to fit an add-on temperature gauge. The ender has been fitted in the correct place if you wanted to use it, or could be replaced by the standard screw-in plug.
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Re: wire going to a sender unit that I should not have ?

Post by philthehill »

The 'L' in the engine number indicates a low compression engine.
The compression ratio of a standard 'A' Series engine is determined by the size/depth of the concave depression in the top of the piston.
The engine may have been changed in the past.
The majority of saloons/travellers have high compression engines fitted whether 948cc or 1098cc engine versions unless specifically requested ex factory.
The 948cc engine does not have a temp sender in the head just below the thermostat.
The 1098cc engine does have a temp sender in the head just below the thermostat.

simmitc
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Re: wire going to a sender unit that I should not have ?

Post by simmitc »

And to round off, a 1965 car would have a 1098cc engine, so the head would have provision for a sender. The rest of your engine number might give a clue, such as 10MA... You can also look at the fornt left hand side of the block, below the side covers, to see that there is either a plate marked 1100 or a flat oval where the plate would be rivetted on. Therer are other indications too, but that's an easy one to see.
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geoberni
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Re: wire going to a sender unit that I should not have ?

Post by geoberni »

miker519 wrote: Mon Nov 20, 2023 8:30 pm The car is a 1965 2 door saloon is there a wiring diagram for this on the club site as all the links that I have tried to follow seem dead.
Thanks for looking MikeR519
Just search for AKD 530, .....the Oklahoma British Car Breakfast Club have a good Technical Library, in addition to a really cool name.....
https://britishcarbreakfastclub.com/technical-library/

There's a useful booklet on testing Lucas Dynamos and Control Boxes on there too.
Basil the 1955 series II

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miker519
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Re: wire going to a sender unit that I should not have ?

Post by miker519 »

Hi all and thanks for getting back.
The Green brown wire is connected to the warning light for the oil filter warning light and the light normally glows a little when warm and if I put it to earth the light comes on. My main worry was that it may have been something to do with the oil pressure not having had the car long.
Re comment about reversing lights can you fit a switch to the gear box? as it would be a useful addition.
The engine is a 1098 as I found the 1100 plate on the side the full engine No is 10V/189E/L21313 if this helps it drives well an does not feel like a low compression motor.
Thanks again for the help as a newbe their will probably be a lot more questions to come.
Best regards MikeR.
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Re: wire going to a sender unit that I should not have ?

Post by olonas »

My reversing light is powered by a pull switch which has a warning light incorporated.
Personally there would be too much involved in fitting, if that's possible to the gearbox. I have heard of a microswitch being used separately.
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Re: wire going to a sender unit that I should not have ?

Post by olonas »

I'm puzzled by that wire connected to the thermostat housing. Unless I have missed something, that location is used by a water temperature sender?
Do you have a picture miker 519? Is it this?
temp. sender.jpg
temp. sender.jpg (101.24 KiB) Viewed 218 times
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geoberni
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Re: wire going to a sender unit that I should not have ?

Post by geoberni »

olonas wrote: Wed Nov 22, 2023 10:19 am
I think that's exactly what Mike has got, an electrical Temp Sensor. :-?
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Re: wire going to a sender unit that I should not have ?

Post by simmitc »

Mike,
There is an oil pressure warning light. It should come on when you turn on the ignition and then go out as soon as the engine starts. The switch is located just behind the distributor.

The filter warning light appears to be connected to a temperature sender. When cold, there is no earth return and so the light is out. As the engine and therefore the sender warm up, resistance decreases and so the lamp start to glow. This is normal behaviour for the setup that you have, but the setup is not normal! There is no connection with oil.

It is possible to fit a different gearbox remote unit, typically from an MG, if you can find one; and that would provide a proper reversing light switch. There are also various microswitch options - try searching the forum for ideas. For example, see topic viewtopic.php?p=690051&hilit=reversing+ ... ch#p690051

Separately, you have confirmed a standard 1098cc engine, and presumably a 4-speed gearbox; in which case the advice on oil in your other oil filter question is correct.
miker519
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Re: wire going to a sender unit that I should not have ?

Post by miker519 »

Hello All
Yep Olonas that is what I have but it has a green/brown wire and lights up the orange warning light at the 9 o'clock position.
The orange oil light at the 3 o'clock position comes on with the ignition red light and both go of when the engine is started.
I think that I will keep it simple and fit the reversing light with a illuminated switch.
Best regards MickR
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Re: wire going to a sender unit that I should not have ?

Post by olonas »

When I fitted the water temp. gauge I just used some spare black wire that was lying around. :roll: Hence that shown in my picture.
However, earths are black and that sender is earthed through the engine.
As an aside, green with a brown tracer is for reversing lamp to switch using Lucas colour codes.
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geoberni
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Re: wire going to a sender unit that I should not have ?

Post by geoberni »

So what we have is a PO that has somehow had the 'bright idea' to have an orange warning light glowing increasingly brighter when the water warms up...

Perhaps it was their way of knowing when to make sure the Choke was in??? :wink:
Only Joking before anyone says it can go in long before the lamp is bright...

Oh what fun we have rectifying Previous Owner (or their technical helpers) efforts.
:roll:
olonas wrote: Thu Nov 23, 2023 10:54 am When I fitted the water temp. gauge I just used some spare black wire that was lying around. :roll: Hence that shown in my picture.
However, earths are black and that sender is earthed through the engine.
As an aside, green with a brown tracer is for reversing lamp to switch using Lucas colour codes.
Lucas Colour Codes of the 1930s (to become British Standard AU7 in the early 1960) changed over time; when first devised, there were no Reversing Lights...
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