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MG Midget and Sprite Technical - Electric Gauges with +VE earth

Has anyone out there fitted an electric gauge to a positive earth vehicle. I know if I insulate the gauge I should have no issues from the cockpit side but my concern/question is will the temp sender still work? I know most senders only have one wire so they must rely on the housing to earth. (Oil Temp Gauge)
Any advice appreciated as always.
Ed H

Why run +ve??
It takes about 10 minutes to convert to -ve....
Onno K

Onno

A couple of reasons really which fall under 'if ain't broke don't fix it' . Its been +ve earth since June 1960 and this does also help prevent rust to a small degree. Plus I have limited time to work on the car before I ship it overseas, hence a capillary gauge would be better but this means dropping sump and welding / brazing a thread to it, which is obviously a much bigger job than running a wire to the sump plug.I still may end up going the capillary route..........

Ed
Ed H

If you have limeted time then why waste it on something like an oil temp gauge?
Just drive it.

But assuming there is no radio fitted it realy only is a case of switching the battery around and swopping the wires at the coil.
Regulator usualy folows without a hitch
Onno K

The reason vehicles changed from positive earth to negative was to prevent rust exactly opposite to your statement. Where did you get that information from?

Regarding a temp gauge. Single wire units tend to operate because the bulb changes resistance and allows a bigger current flow. However that current flow is determined by also the "mean" voltage which if directly from the battery also varies and the temp reading would not be constant.
This was overcome many years ago by adding a voltage stabalizer to the circuit (a simple bi metalic strip). That was all fine but modern gauges can be different in so much as many use on board voltage stabalization which would be electronic and therefore polarity sensitive. It depends therefore which aftermarket temp gauge you buy would determine your actions.

Far easy I am sure you would agree to change vehicle polarity. You may also want a modern CD player?
Bob Turbo Midget England

What Bob says. You need a regulator to match your gauge/sender combination; and as you say, insulate the gauge body. It may be your existing regulator for the fuel gauge might be ok... I like the capillary gauges for temp, and have additional one for oil.

A
Anthony Cutler

June 1960 means no regulator
Onno K

This thread was discussed on 27/01/2012

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