[v12-engine] Coolant low-level sensor wire identification HELP please?

Hi all, as I recently mentioned I’ve released some picts.
of that mysterious coolant leak I discovered at my metal expantion
header tank. This shows the culprit being that tiny tube
coming out on top of it, wricked loose its soldering junction.
It comes/goes from/to that radiator twin-port; I think an airbleed
feature.

Now I have a question about that low-coolant-level-sensor.
I can’t find the wire that would go to it?
Has somebody an idea, since I can’t remember having disconnected it;
nor where it went? It can’t just have disappeared, ain’t it?
This seems not to be covered in any manual?

Does somebody can give perhapse the wire color-code, so maybe I can
track it down?

Much thanks in advance for the help-out.

Harry '87 HE-V12 Sovereign (Belgium)–
Zarri-X
Brabant, Belgium
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At 19:55 2006-01-20 +0100, Zarri-X wrote:

Does somebody can give perhapse the wire color-code, so maybe I can
track it down?

I don’t have an XJ12, but the wiring diagram for the 1988 XJ-S shows it to
be a WR (White with Red tracer) wire, rhat runs through the low coolant
unit (which is most likely a voltage comparator - it also has connections
to ground and to a voltage source). The wire between the coolant unit and
the warning lamp is WU (White with blUe tracer). The wire routes through
the left bulkhead connector. This is valid for the 1988 XJ-S at least, but
I suspect it is very similar for your 1987 XJ12.

IIRC, the connector on the end should be a 0.25" female spade connector.

— '88 Jaguar XJ-SC 5.3L V12 (LHD) ‘Black Cat’
Sean Straw '85 Jaguar XJ-S 5.3L V12 (LHD) ‘Bad Kitty’
Sonoma County, California '91 Jaguar XJ40 4.0L (LHD) ‘Trevor’
http://jaguar.professional.org/ '69 Buick GranSport 455 V8

Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !

In reply to a message from sean.straw%2BJaguar@mail.professional.org sent Fri 20 Jan 2006:

Sean, thanx for the wire-color code info, I will have a look after
it, and keep you and the Forum informed.
Just for your info, I’ve already figured out that the low-level-
coolant unit, works on a capacitive-oscillator principle. It’s a
round tube besides the passengers side fusebox, labeled RKC5259J,
on JDHT.com drawing MM8246.
There’s NO comparator or so in it, just a CMOS-oscillating circuit,
that starts oscillating as long submerged into coolant fluid.
At least at mine, when you have a single wire probe tip C43222.
See JDHT.com drawing LE8148. Therefor, to assure a good
functionality, the metal expantion header tank is grounded to the
chassis. I’m tracking down the schematic from it, and will release
it in a pdf, so every one can fix it when malfunctioning.
For the electronics technicians, this works on the same principle
as the LM1830 circuit from NationalSemiconductors.
You can Google for its datasheet in a PDF-file.

Greetings, Harry '87 HE-V12 in progress–
The original message included these comments:

Does somebody can give perhapse the wire color-code, so maybe I can
track it down?
I don’t have an XJ12, but the wiring diagram for the 1988 XJ-S shows it to
be a WR (White with Red tracer) wire, rhat runs through the low coolant
unit (which is most likely a voltage comparator - it also has connections
to ground and to a voltage source). The wire between the coolant unit and
the warning lamp is WU (White with blUe tracer). The wire routes through
the left bulkhead connector. This is valid for the 1988 XJ-S at least, but
I suspect it is very similar for your 1987 XJ12.
Sean Straw '85 Jaguar XJ-S 5.3L V12 (LHD) ‘Bad Kitty’


Zarri-X
Brabant, Belgium
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Zarri-X wrote:

In reply to a message from sean.straw%2BJaguar@mail.professional.org sent Fri 20 Jan 2006:

Sean, thanx for the wire-color code info, I will have a look after
it, and keep you and the Forum informed.
Just for your info, I’ve already figured out that the low-level-
coolant unit, works on a capacitive-oscillator principle. It’s a
round tube besides the passengers side fusebox, labeled RKC5259J,
on JDHT.com drawing MM8246.

Very informative Harry and thanks for info to the group but what SIDE is
that .
Cheers Steven

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