Wiring question for black and grey water tanks

[schmed613]

I installed a new black water tank last yr. there is 3 wires ( white,grey and black)coming from coach to monitor black and grey tanks. New tank has 4 screws in the side all vertical from each other. My grey water tank has 4 also but one is off to the side ( and the white wire from coach goes to it)
The black wire goes to indicator wires on black tank. The grey wire to grey tank. And so far I know the white goes to the offset screw on grey tank but what about the black? There's no screw like the grey has?
Also my monitor in coach only has three lights. Empty. Half. And full...

[Skip426]

I see your not getting replies . Could you provide more information , RV , year and make, & monitor panel brand .

If you take a min. and from the User CP, fill out your RV information in the " Edit Signature " drop box , it will appear under your posts and you won't have to type it in every time .
Like mine does below.

[schmed613]

Thank you very much I will do that shortly!!