Fresh Water & Sewage Tank Level Monitor not working

[Rocketman]

New to me 2009 44 Sojourn.
Both tanks indicate empty all the time.
Water tank completely full - still shows empty. Tank is clean.
Holding tank about 3/4 full - still shows empty. Tank is not very clean on the inside.
Both tanks are plastic.
Sensor system is the SensaTank II system using the probeless external sensors attached to the outside of the tank.
All wires appear to be original to the boat and all solder joints and stuff look to be in good condition.
I have not pulled the actual gauge and verified any issues behind it.

Any suggestions on what is going on with the system.
I know I can try and clean the holding tank but this would not resolve the water tank issue.

Thanks.

[Cooler]

Have you checked the fuse panel and turned on all breakers? I had the same issue and discovered my waste tank monitor was connected to one of the extra accessory breakers. Strange for me cause I thought the shower or head breaker should have accomodated that. er

[Rocketman]

The system is on and working. It just always shows the empty LED lit up when you select the fresh or holding tank.

[Midnightsun]

I had a similar system (external sensing tape style) on a previous boat. After a couple of years the controller went bad, swapped it out under warranty. After about a year of ownership, the new owner had the panel go bad again. He chucked the system and installed NMEA 2000 system all around which reads the tanks via not sure what?. Point is there is not really anything that can go wrong with the sensors taped to the sides so the issue is very likely the controller. No the sensors do not go bad like the internal ones but the controllers do seem to be questionable when it comes to long term reliability. Hold onto your hat when you get the price of the new controller, might as well buy a new system or at least it was in my case.

[chpsk8]

I've used Profile sensors in the past. They are fairly inexpensive at $150 a tank.
http://www.newprovidencemarine.com/product_display.html

My fresh water tank gauge isn't reading right, it's a probe style and it's shot. Pretty sure I can sub in a new probe to get mine going. If yours is an outside the tank sensor I'd take a serious look at the Profile ones. BTW he sells these to companies that put their own brand on it and sell it for way more.. he's the actual source.