On my boat, I have a Venus GX, and I thought it would be nifty to use it to survey the tanks (1 fuel, 2 water) as well. There are already tank meters on the tanks, which are hooked up to a shared analog gauge. I have measured the fuel tank meter, which shows 180 ohm when the tank is full. However, there is a resistor of sorts on the gauge, which shows about 150 ohm, hence the combined resistance is 82 ohm. Consequently, when hooking up the VGX to this setup, it says that the tank is about 45% full.
The obvious fix would be to disconnect the analog gauge, but I would certainly prefer to keep it as well. Is there a way to resolve this?