I've had the same problem as other RV owners with the Fresh, Grey and Black tank level indications being wrong. I've tried to clean the tanks using several different suggestions, to no avail. I did however, read that Horst Mirical probes would do the trick.
Well they did, to and extent. I seldom carry fresh water so that wasn't a problem even though it shows 1/3. The grey was also showing 1/3. The Black showed 2/3 full (I know it was empty) but, the lights were very dim when the button was pushed.
I just replaced the grey probes--works prefect now.
Replaced the black probes-- same indication, 2/3 very dim. Seems to be a short of some type somewhere! Tracing the wires is am impossible task as they are buried in the spray foam insulation along the refrig wall, along with several other wires and cables.
Result: Horst probes work, simple to install with no new holes to drill. Tools required, two 3/8 open end wrenches, and a pair of pliers to remove the old rubber seal. Wet the new probes for lubrication and push to install. Tighten the inner nut until a good seal is achieved, wire, then second nut. ENSURE your tanks are empty! I removed all four probes then installed from the top down.
Tree
Tank indicators
Linear Mode
