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Another little electrical question - fuel gauge.

Jim_Newman

Jedi Hopeful
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Does anyone in LCBland know how the fuel sending unit and gauge work together with the 12V negative ground.
I have the new tank installed and a new sending unit in place but the old gauge is with Nissonger for rebuilding.
I assume the sending unit is simply a variable resistor. So in the meantime, I have measured the sending unit resistance and found that it <span style="text-decoration: underline">increases </span>as the full level in the tank <span style="text-decoration: underline">increases</span>. Hence the gauge seems not to be an ammeter since the current would decrease as the fuel load increased.
I'm confused.
Any thoughts anyone???
As always
Cheers
 
Since they are made like this

fuelsender.jpg


Wiperposition / lenght resistancewire / groundpoint

The increase /decrease depends on the black wire attached on the upper side (connected to ground) or the other side ...

Hans

Edit 1, found the pictures source and far better info
https://mgaguru.com/mgtech/electric/et214.htm

Edit 2, Gauge's ground is changed too of course
 
I can tell you from experince that switching to negative ground has no effect on the fuel gauge. It works the same either way.
 
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