Originally Posted by bwalz
We have a Wema water gauge on our recently purchased '05 Mainship 400. It has a switch with 3 settings; I, center, and II.
It will only read the water level on I and I'm wondering if that is the level for both tanks or should each tank read separately?
Originally Posted by Capt GB
The 400 only has one sending unit. Align the valves so both tanks are tied together and the single sender will register the correct level.
BW, our sister-brand boat has two freshwater tanks, connected by a cross-over hose, and only one deck fill.
We have WEMA tank gauges (separate gauge for the holding tank), and with only one sender inserted into the input side freshwater tank.
Our gauge doesn't have your options, though. Our freshwater tanks self-level, so only one sender is required.
Perhaps you have two deck fills, and your freshwater systems can draw independently from each tank? Otherwise, I'd assume you've maybe got a cross-over hose, your tanks self-level, and your gauge switch is superfluous (perhaps meant for a different application, but installed in your boat because it was handy that day...)