water level indicator

[Rnightengale]

I have a J Flight pull behind travel trailer and the panel that shows my tank levels (fresh water, grey water and black water) seems to always show the fresh water as being full and black water as being full. has anyone had the same issue? not sure where to start looking for the problem and local RV shop is backed up for months
Roy

[JFlightRisk]

It's possible the indicator panel is bad, but I would crawl underneath, and see if the top sensors are being shorted to ground by something. That would give you the false reading.

[Jagiven]

Both the black and grey tanks showing full is fairly common complaint. Especially with the black tank. TP gets hung up on the sensors and gives a false reading. With the grey water, I believe it is old greasy slim that triggers the signal. Making sure lots of water is in the tank before dumping is key. I also add water softener periodically when my sensors are acting up. I make sure to add about 5 gallons of water after dumping, and the water softener, sometimes I add liquid laundry soap too (does not foam). The solution sloshes around during my trip home, and during the next trip to camp, and washes down the sensors. The water softener is a water wetter, which allows the water to penetrate old dry "stuff" easier" so it will soften.

As for the FW tank, usually it reads correctly. I have had an issue, but do not recall my fix. But I did not add any chemicals to the tank.