Hello:
My dog recently chewed up several of the wiring systems underneath my new travel trailer

. I have been able to repair all but the wiring assembly that monitors the water level in my grey tank. I am having trouble finding a replacement wire assembly without buying a whole new monitor kit.
The frayed wires are there to repair, however, the problem is that the one piece that is missing is a small black tube where three of the sensor wires from the holding tank feed into one side(full, 2/3, & 1/3). From the other side of this tube comes out one single wire which attaches to monitor. The other wire which which is connected to the monitor is the to the the fourth sensor (empty).
This tube looks almost home made for a factory item-it looks like 3" long piece of 1/4" drip line,crudely cut, and with a dab of glue from a glue gun to seal each end. This description is based on how the black water tank wiring appears.
I am hoping i can maybe fab a new one, however, I have no clue what is inside this assembly. Are these monitors based on potential, resistance,or what. I sure there is a diode or resister in this little wiring assembly before the wires joined into the single feed. I hate to discect my good assembly from my black or fresh water tank to verify.
Does anybody have any ideas what is in this assembly?
Thanks,
Michael