Black Water Holding Tank Level Indicator

[Mikwallace]

Greetings all! Im a new to me 1998 Carver 405 AC owner and working through some things figuring out how the systems work, or don't work.

The Holding Tank indicators do not indicate waste level in either holding tank. Is there a button to push to activate the sensor or does it indicate constantly? Only one time have I seen one of the indicators work and it showed empty (of which I'd just emptied the holding tank, so that was expected). I'm not sure if it was just a coincidence or not?? Here's a picture of my indicator. It's a VACU-flush system.

Thanks!

IMG_3630.jpeg

[Cooler]

There is a flat toggle switch in your DC panel for the indicators. That needs to be in on position. My tankwatch is tied into an accessory switch. My indicator only shows empty, and then red when I am almost full. Mid range light does not light up, but I am OK with that. er

[g36]

There's a switch in the dc panel 12v column 1 and it's the very bottom or one up that turns this and the water tank monitor on that's in the aft head. I would verify power . Since the boat is new to you I might use the head some keeping an eye on how full the tank gets by eyeballing it under the hatch and see if any of the lights do work since you haven't any history with the boat before diving into the next option. The next thing is to go to the top of the holding tank which is under floor hatch in front of aft cabin tv. Theres a clump of white wires these are the float/sensors that make this work. I had to open my tank (not pleasent )and was able to unscrew the top and remove and clean these sensors (preferably after a pump out ) I added quick disconnects to the wires so next time I can unplug and remove easily whenever the next time is.

[tomschauer]

There is a good chance the floats are fouled with paper and other nasty stuff.
If you are sure the power is on at the 12vdc panel, get the boat pumped out. You should see green lights.
While at the pump out dock, run water into the toilets. The green light should go out after one or two flushes. No light will then be lit. Keep flushing.
The yellow light will light when you hit halfway. It will stay lit until you hit full. Then it will go out and the red light will light.

[Mikwallace]

Thanks for the info. As I dig through the systems on this boat I learn something every time. I did look at the fwd holding tank cap you refer to and one of the probes was extended upward so high it almost touched the bottom of the wood hatch cover that supports the seat cushion. It was late into the evening yesterday when I noticed that, so I didn’t go any further for fear of breaking something. I’ll check it out when I return next week and report my findings.