After removing the board that was our old control panel I fished out the shunt wires and tested to make sure they still had a connection to the back of the trailer. Also at the same time I found the brown insulated multi conductor wires for the water tanks sensors.
I added some wiring for the Voltage measurement and whalaaa, with two cheap harbor freight meters I could monitor the voltage and amperage draw from the battery. This picture is after I had the new board installed over the existing hole, more on that in the next step.
For a while we got by with this setup, open up the overhead cabinet and balance multimeter’s on top. During this time I took some readings from the freshwater tank sensors to see if they could be made to function. I also built a little control board from one of Zeppliniums circuit diagrams. Here is a post about what I found with the fresh water sensors.
The LEDs go out as the water tank empties – or not 😉 Going to have to spend some more time with this part for sure.