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Topic: Factory Holding Tank Sensors (Read 296 times) previous topic - next topic
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Factory Holding Tank Sensors
Been reading this morning about factory holding tank sensors.  I need to disconnect the wiring so I can completely remove the gray water tank in preparation for other work.  Are the screws the wiring attaches to also the sensors?  As in, do they go straight thru into the tank?  Or can I remove the screw enough to take the wires off, without disturbing the sensors and perhaps causing leaks?

I can always break and re-splice the wires, which I'm quite comfortable doing... just don't want to dig out the soldering iron and heat shrink if I don't have to.

Have no reason to believe (yet) they don't work, so I'll save the "chuck 'em and replace with SeeLevel" money for when it's shown to be warranted.

Chip
2000 Front Lounge
Re: Factory Holding Tank Sensors
Reply #1 –
I am reasonably confident that the screws themselves are the sensors.  Turning them is likely to lead to leaks.  Were I you, I would mark, then cut the sensor wires, then reconnect with butt splice crimp connectors with heat shrink cover and adhesive liner.  They are more reliable than a soldered connection, which can be brittle at the edge.  They are available at some hardware or auto parts stores, and at most marine supply stores such as West Marine.

Ken F in NM
'08 MB
Re: Factory Holding Tank Sensors
Reply #2 –
Hi Chip,

On my 2003 LD, there are screws attaching fairly thin wires to the sensors. I easily removed the wires when I was having problems with the gray tank readout. They were color coded if I remember correctly. I don't think the wire attachment screws had any effect on the integrity of the sensor in the holding tank.

I suggest you take a photo of the wires before removing them so you can reattach the wires to the correct sensor. 

By the way, I would not be without my Seelevel tank monitoring system. Simply the BEST addition we ever made to our rig!

Good luck with your project.
Steve K.
Steve K

2003 Mid-bath
Re: Factory Holding Tank Sensors
Reply #3 –
Looked into it this afternoon.  On my 2000 FL, the tank sensors are not the screws themselves.  The screws are about 6-32, and are about 3/8" long.  Screw heads are not too corroded, and the concealed part of screw was pristine, so they're obviously not submerged.  I'll clean up the connections upon replacement, and we'll see if it still works...  Might go stainless steel, depending on what metal they screw into.

But in the end, they don't appear to go clear thru tank wall, but instead stop within whatever the sensor body is. (White nylon device about 3/4" in diameter, with two 1/8" diameter nubs protruding on either side of the screw.  At least on mine.

A quick sharpie note on the side of the tank ensures I'll get them back in the right place.

As a side note, I'm seeing lots of flakey grounds for various circuits.  I think I'll be cleaning up each one as I pass through, and hitting them with either spray-on battery post goo, liquid electrical tape, or some other treatment...  Probably not 5200 though, as that stuff is more of a permanent commitment.

Next challenge is to undo the plumbing connections without breaking any pipes, or the tank.  Connections via short length of hose should be straightforward.  Outlet connection looks interesting -- it's a hose clamp around the snout molded into the tank.  That implies the tank is flexible enough to conform to the pipe going to the valve assembly.  I'll watch for sealant there.

Chip
2000 Front Lounge
 
Re: Factory Holding Tank Sensors
Reply #4 –
Chip, thanks for the update.  Learning all the time - I stand corrected.

Ken F in NM
'08 MB