failing fresh water holding tank gauge or probe?

[kbniehaus]

2004, 320, the level indicator gauge for my fresh water holding tank reads ALL levels regardless how much water is actually in the tank. I cleaned the sending unit tank probe with no effect. Before I replace the probe I am wondering if it could be the receiving unit switch. Anyone have any experience with this issue?
Thanks!

 

[boatmailster]

2004, 320, the level indicator gauge for my fresh water holding tank reads ALL levels regardless how much water is actually in the tank. I cleaned the sending unit tank probe with no effect. Before I replace the probe I am wondering if it could be the receiving unit switch. Anyone have any experience with this issue?
Thanks!

I've seen that before.
1) display is bad - disconnect sending unit and if display still shows all levels - replace display
2) cracked top of sender and short by water inside crack - you could try to dry sending unit (remove it from boat) for day or two, reconnect outside tank and if read empty - replace sender or fill crack with slicone, epoxy or something similar and let it cure before reinstalling in tank

 

[kbniehaus]

Thank you boatmailster. I'll use your suggestions to diagnose. Appreciate the help.