Installing the black water tank sensor ended up being a bit of a project. As of today, we are about halfway through. The starboard side is working. The port side keeps coming up with either an open circuit or a short. Unfortunately, the error codes are only helpful on a very basic level.

Installation involved running electrical wiring from the main breaker panel to the holding tanks located in either hull. Waponi’s current wiring is a network engineer’s nightmare. 98% of the rat’s nest of conduit, cable, and wire is not labeled. The one saving grace is that there is, in fact, conduit.


  1. Two 25′ spools of 18 gauge stranded “zip line”
  2. Fish tape, aka pull string
  3. Solder and soldering gun
  4. electrical wire strippers
  5. electrical tape or tape paint
  6. masking tape
  7. marriage counselor

The process:

  1. Open electrical panel and resist urge to start rewiring the entire boat.
  2. Remove all items from the storage space under the settee on the starboard side.
  3. Determine how the wires get from the electrical panel to the starboard head. (There is a light in there, so the wire has to get there somehow. We think. Maybe.)
  4. Take everything out of master head closet and marvel at all the things I thought I needed upon moving onto Waponi and resist the urge to purge.
  5. Remove master head closet shelving and back access panel. “Oh, so that is how you remove the water tank. Let’s not ever have to remove the fresh water tank.”
  6. Have Caroline crawl into the space under the settee.
  7. Run wire from electrical control panel to the conduit under the settee, through the hole in the bulkhead for existing wire which can be accessed through the master head closet and then up and over the head ceiling following the path for the existing wire we believed went to the lighting for the starboard hull. “Wow, that took exactly one spool of wire.”
  8. Drill access hole for wire above black water tank.
  9. Discover existing wires for lighting for different version of boat. “Well, I suppose if I need a reading light in the head…”

Now we are ready for the temporary installation (we have to make sure it works before making more holes for permanent installation) of the tank meter. The meter is two 12″ strips which have to be connected together because we have a 24″ tank. One strip has one tab removed to mark it as the bottom strip. The second strip has two tabs removed to mark it as the top. The two strips are soldered together. This connection is then connected to the wire we ran to the electrical panel. The wire at the electrical panel is connected to the tank level panel and, “We have a reading! It lives!”

But, wait… we have two hulls. There is more work to be done. The process for the port side head is similar, so I will just highlight a few of the differences:

  1. The port side of the settee is food storage. Pro tip: make sure lid on the Costco container of olive oil is securely closed before moving it.
  2. There isn’t quite as much space on this side of the settee as it the access for the salon heater fan, the water pump and the fridge. The heater fan also means the lines for the heater full of hot liquid are running through this space.
  3. All three of took a turn in the hole for this one.
  4. The run for this one went from the electrical panel into the conduit under the settee across the salon. From there it went through conduit under the stairs then behind the oven (did I forget to mention we had to take the oven out?) and through the bulkhead into the head.
  5. 25′ of wire was not enough. More wire was purchased and soldering in the settee hole was necessary.
  6. Oven was put back in place. “Ryan, what is this board here for?” Ryan’s response, “That goes under the oven.” *head, desk*

We get everything taped together, soldered and plugged in. “It doesn’t work!” We get an error code on the panel indicating either a short or an open circuit. We replace the wire with a different gauge and a continuous length. We still get the same error codes.

Now we get to call tech support and see if there is a solution. In the meantime, the starboard side is functioning. We know it can work; we just have to get the other side to cooperate.

Oh, we also labeled all the wires and left pull string in the conduit. If you are going to do a project like this please make it easier for the next guy because the next guy is going to be you.

I am short. 4’11 ½” (That last ½” is really important.) India outgrew me a year or two ago. Aside from Rover, this makes me the smallest person on the boat.


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