We have a 2001 C and I can see the black tank from the toilet drain, sensors stoped working for the black and grey about 4 months after we bought the unit, after that I simply watched the level of the black tank and eventually can tell how full it is by the sound when flushing, grey tank tells me it needs dumping when the water rises in the shower tub.
Of the four sensors only the one accurate is the propane, even the fresh water sensor indicates wrong, do not waste money and time trying to fix the sensors, learn to gauge when they need dumping, instead of worring about useles things that won't work no matter how much money you trow at them enjoy the unit, it is more rewarding.
navegator
