Does anyone know if I have to change the voltage stabiliser when I change from POS to NEG earth system?

Thanks in advance.

No it works on thermal and resistance only with a make and break contact.It is as such polarity unconscious
In electronics terms it is a very unusual regulator

No need to change it. Its just a bi-metalic contact that opens and closes. Same as the flasher can. I run my Mk1 S with neg earth.

Uses 1950 technology, haha.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

I thought I had already replied to answers here, but there is no sign of it.
The question was prompted by some suppliers offering a NEG earth unit, a POS earth and one especially for the mini but not specifying which earth!
Easier to ask now.....
Thanks for replies and for explanations.

drmini: "Uses 1950 technology, haha."
Some of us are the result of 50s technology.

If you have one that is u/s, why not open it up and convert it to modern technology. All it takes is a cheap IC.

I bought an electronic one from wombat and tucked it into the wiring loom. Now the fuel gauge doesn't read lower the faster I go

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

If new units on the market are integrated circuits rather than the old bi-metal strips, would the new ones need to be polarity sensitive? Hence the need to specify earth for modern units?

Yes they will be polarity conscious and will most likely be for a negative ground car.
I imagine they use a three terminal regulator of a variety that tolerates small difference between input and output
Will check my supplier for part numbers and see what is available .The garden variety come in positive and negative types.
They are 10 volt low drop regulators

The voltage stabiliser part for mounting to the mini speedo housing came from this link at Holden in the UK. They have (-) and (+) and (mini) units hence my question about polarity.

https://www.holden.co.uk/displayproduct ... de=070.019

Thanks Ian_B for your comments.

Looks like they have reproduced the original voltage stabilizer (1967-1985) with 2 styles because the new ones are polarity specific. http://www.somerfordmini.co.uk/eshop/in ... page&id=83

"C34770POS VOLTAGE STABILIZER 1 BR1310/00; 1967-69, positive earth systems.
C34770A VOLTAGE STABILIZER 1 BR1310/00; 1969-85, negative earth systems.
Originally there was only one stabilizer (Smiths no. BR1310/00) fitted between 1967 and 1985, irrespective of vehicle electrical system polarity. Today, however, the manufacturer produces polarity-specific stabilizers - be sure to order the correct replacement for your Mini."

Are you using your old one or are you buying a new one?

For those interested in the workings of and the solid state modification of Smiths voltage stabilizers, the following links to a doc on the topic.

https://www.minimania.com/Smiths_Voltage_Stabilizers

I found this after I had modified a faulty original type in my Triumph Spitfire in 2000 using an IC from Dick Smith Electronics. The ICs, 7810 and 7910 for -ve and +ve ground are readily available on eBay, quite cheaply.

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Clive G
1969 Mk II Cooper S
1970 MK II Cooper S
1963 Triumph Spitfire
1982 RX-7 Series 2

I think the clubby ones and roundie ones aint interchangeable