Holding tank sensors on 2017 Montana

[jstadler]

I have the In Command control unit. My tanks fill and the sensors do not show any indication of water in the tanks. The sensors are supplied with 7 volts DC from the command board and a return line from the take to the command board. The command board put out 7 volts as it should. However, when you connect the common wire for the 7 voltes you get now votable showing on the common wire and no return voltage from the sensors. I took a Volt Ohm meeting and disconnected the common wire that sends the 7 votes to the sensors. I took a reading across the common to ground and how zero ohms which would seem to me like the common wire is shorted out. Can anyone shed some light on this. It's annoying to own an expensive trailer that can't tell you how much water is in three separate tanks. Thanks