Dale to access the sending unit you have to get at it from the next bay back, the plumbing bay! That means ya probably gotta pull one of your tanks, water or holding, to get at that panel. I too have a bad sending unit and already have it sitting in central spares.

Got that info from Dale who already been there done that.

Maybe if you want this winter when we head south we can help each other and get them both done.

I removed all those screws on the spot that Jon mentioned before I knew what and with that plate removed you can look in and see what is up but I think that is for actually dropping and installing the tank.