The V8 Owners Forum -

I've got hold of a Smiths coolant temperature gauge and was wondering if anyone knew which way round to wire it in.
There's a female connector (marked 1) and a male connector (marked 2) on the back. Which attaches to the voltage stabiliser (or is it likely to have an inbuilt one?) and which goes to the sender unit in the engine?

Thanks for your help,
William

to check the polarity, get a PP3 battery and connect across the gauge poles, when the needle moves the right way (towards HOT) the pole at the negative
end of the battery, goes towards the sender, and the pole at the positive end of the battery should be connected to the ign 12v +ve.

as for inbuilt regulator.. mm doubt it!! what is the gauge out of originally, and what car are you fitting it into ??
Ford Regulators, and sensors are set to work at approx 7v, but rover/BL seems to be 10v (ie Mini)..
some gauge kits come with sensors balanced to work at straight car voltages, so are therefore not as accurate.. only giving a rough indication

If this is a typical Smiths gauge, it will have a bi-metal strip and coil to heat it. If so, then the polarity won't matter - the MGB fuel gauge is this way and the similar Smiths temp gauges are almost identical.

Thanks for the info.
I'm told the gauge came from a Jaguar XJS v12. Its to go on an old Landrover 3.5L v8.
the needle does only move with the gauge wired up one way, so the polarity does seem to matter.
The engine is playing up at the minute, so I haven't been able to run it long enough to see if the gauge is working yet

Cheers
William

Something that nobody else has confirmed is yes the smiths gauge does need a regulator. You need to also make sure you have the right value sensor for it to be accurate as well but maybe all the smiths sensors are the same value, not sure on that tho.