Another option is installing Horst Miracle Probes. They fit in the same holes that the OEM probes use, and use the same wires. I have bought a set for black tank and both gray tanks, but have not installed them yet. Have heard that they really do work.
2003 Ford F-350 V-10 Crew Cab 4WD Long Bed
2004 Jayco Designer Medallion 29 RLTS 5th wheel
Bill, Gayle, and Mindi (dachshund)
Retired at last !
Nothing is foolproof to a sufficiently talented fool.