Tank sender wiring question

[pappaecho]

My Evasion 32 has a 33 gallon fuel tank with sender and gauge, which worked when the Perkins 4108 was in situ.
The new Beta fitted a couple of years ago did not have a wiring loom which included the tank sender and gauge. The gauge has three connections presumably +ve, -ve and ?? -some sort of reference?
The tank sender only has two wires presumably a resistance in the circuit between the +ve and -ve . Any ideas greatly received?

 

[Andrew_Fanner]

I have a similar problem, after some wiring was altered to suit Boat Safety the fuel gauges don't work. I am advised that the third terminal is "ground" and in a car would be the earth path from the sender and that it is lkely that the wire clipping has inadvertanly severed this connection. Given that the gauge flips right to the pin I can see what this is about: the sender variable resistance is not part of the circuit at the moment.

My understanding, and doing this without graphics could be fun


tank sender ------wire------ve terminal on ¦gauge¦+ve terminal--¦ ¦
wire-----ground ground

If any expert can link a proper diagram that's two of us grateful