83 T3 westy fresh water tank level sensor

[Swordfish93]

Hello, I have a old fresh water tank system with the electrical contacts going down the side of the tank. How do I wire these up to the monitor that goes in the galley? I can't find anything about it. Can I just put in a a newer model sliding sensor in the tank and still use the led water level monitor? Pic for reference
tank

[hotpod]

I have two of those, both working. One has never been removed so I used it for reference last time I reinstalled the other one. I should have photos somewhere but cant find them. I will take a photo this evening.
I have the Westy wiring diagram but it doesn't show the colours.
I presume you have the little black square thing which all the wires come out of?
If I remember correctly, the earth ( shared with the water pump I think and I think it is black) goes on the bottom one and the others speak for themselves pretty much with their length. then it is just the green cable from the black box which goes to the leds below the cooker.

 

[hotpod]

I think if you put a newer sliding level sender in it would be tricky to get it working with the westy leds. But there are smarter brains than mine on here so maybe someone will prove me wrong. If you dont have the little black box with the coloured wires coming out then that might be your best solution.

[hotpod]

The top pic is the 1983 interior I fitted into a van and the bottom pic is the completely original 1985 one which as far as I can tell has never been apart.
They both work well and show me the water level. The looms are slightly different because the one I fitted was missing some of it. 
So in the bottom photo, there is a brown earth from the westy loom on to the lowest level, followed by white one from the black box, then the yellow for mid and green for the top, and the other green at the top point which goes back into the loom goes to the LED's.
The black wire from the black box is a mystery. In the stock westy it loops out of the short wiring sheath from the black box and back into it. On the earlier van it has a female spade on the end but nowhere to go.
In the top photo, I used black cable for the earth.