As I understand how these work there is a sensor at each level with a resistor between them. The level is determined by the resistance of the circuit.
I think I would be looking at the wires on the tanks to see if they are still all intact.
These sensors are not particularly accurate but what Donc13 reports seems more as if something has changed not just inaccurate. He also reports rough road so maybe some of the wires on the tanks came loose?
Exactly! Fresh water tank always full... That's a short. Black tank, now seems ok. Grey tank.. Will check wiring.
It's the fact there is only a nine wire connector into the panel. Let's say a common +12v for all. Has to be a ground also.. That takes care of 2 wires. 1 for the LPG gauge, no wires needed for battery (other than the already accounted for +12v and GND). So +12V, GND & LPG is 3 leads. Leaves me 6 wires yet to account for.
Each tank has 3 level wires and 1 hot (+12v).
Now I suppose you could tie all the individual 1/3rd, 2/3rds and Full sensor leads to each other... That'd be 3 more wires to the sensor panel (instead of 9 wires) and then just switch the +12v wire to the proper tank.
Ahhh... Screwed up my math.. 3 +12v leads.. One to each tank... Then 1 full lead for all tanks, 1 2/3rds lead for all tanks... And 1 1/3rd full for all tanks.
That's 6. And that fits!
I'll dig more when I get back home.