Cleaning the Holding Tank Level Sensor at 5 AM

Yep.  That would be me.  I've always been that way.  When I owned a computer business, I'd been known to go to work at 3 AM to fix a computer that had a problem I couldn't diagnose, but when the answer came to me at 3 AM, off I'd go.

I installed two Electrosense tank level gauges a little over a year ago.  One for the water tank, one for the waste holding tank.  The water tank gauge has always worked perfectly, but the waste tank gauge started acting up some time ago.

We had just pumped out the waste tank.   Even though it was empty, two indicator lights were lit, 10% and 80% full.   They're supposed to go up incrementally, as in 10%, 20% etc.  The ethernet connection had gotten wet and I suspected corrosion, but a good sanding of the connections didn't fix the problem.

I swapped the fresh water ethernet cable with the waste, and the fresh water display showed two lights, so the problem is with the sending unit.  What could it be?

I woke up at 5 AM this morning.  Actually, I'd been tossing and turning most of the night because the wind was blowing the furniture around on the aft deck over our heads.  But in that half awake, half asleep state I found myself in, a voice said "take the cover off the holding tank and clean the sensing rods."  The voice always says things like that.  It never says cool stuff like "get up and have a beer."

So I got up, went to the forward junk store room, lifted the access panel from the floor, and undid the 20 nuts holding the tank's access cover in place.  I shined a light inside.  Yuck.  I could see the rods for the sending unit and they were covered in gunk and barnacles.  Yes.  Barnacles.  We flush with salt water.   Why a barnacle would want to live in there is beyond me.

So first I wiped the four rods down with paper towels, and then took sandpaper to them.  I got them pretty clean, if I do say so myself.  I put the access cover back on, tightened up the 20 nuts, put the floor panel back, washed up real good, and dashed up the stairs to the helm station.

I pushed the display button.

The same two lights came on.   Dang.

I guess that voice isn't so smart after all.   No victory beer for me this morning.