Holding Tank Sensor Issue

[Steve Hutchins]

Our black and gray tank sensors are not giving accurate readings, the gray tank is stuck at 69%. It looks like what monitors the tanks are pressor sensors from Serta, "Setra Systems Pressure Transducer 2091001PG2M45P1".  I have the CMP-20 monitor panel.

Although a little pricey to replace, I have no problem replacing them if it is a sure fix. Does anyone else have this setup in their coach and had success changing them?

 I tried to have the tanks hyro-cleaned to see if the sensors were plugged but he was afraid his pressor nozzle would ruin the them.  I've located the sensors behind the wet bay partition, a little tight to get to.

Thanks, Steve

[Bill Lampkin]

You can check the sensors for resistance with your multimeter. Make sure the tank level system is off (no display). Make your measurement; if the sensor is open (infinite resistance) you have a bad sensor. Otherwise, use your leveling system to tilt the motorhome away from the sensor end of the tank and remove and clean the sensors.

[Steve Hutchins]

Thanks Bill,  with access being extremely tight to the sensors Ill probably just buy new ones.  One time wedging myself into the compartment, replace with new.  If the old still work I'll have some spares.

[Dan Johnson]

I have issues with my tank monitors also. The fresh starts at 15% When filling the fill valve shut off at 100% but was about 20 gallons short of full.Is the sensor tied into the fill valve? I wonder if I should just go to the SeaLevel system and be done with it?

[Bill Lampkin]

Under Coash Assist, you'll find how to calibrate your Aladdin sensors.

[Steve Hutchins]

Dan, I would think there would be some kind of sensor mounted on or in the tank giving you the reading on amount of water in the tank, not something tied in with the fill valve.  The SeaLevel system is something I'm considering but I'd like to keep the original system if I can.  This allows me to keep using the CMP-20 monitor panel without running new wires to the monitors I would have to add.

Bill, I looked into calibrating the Alladin system but looks like I don't have that system.

We will be at the Rally next month in Quartzsite, hoping to talk to fellow Beaver owners to find what solutions they have come up with.

Cheers,
Steve & Shellie

[Dan Johnson]

Steve
I have the same system as you. Let us know if anyone has answers to the problem.
Dan

[Eric Maclean]

Hope this helps
Eric


http://beaveramb.org/forum/index.php?topic=3954.0

[Steve Hutchins]

Thanks, I've looked into calibrating the CMP-20 panel but could not find the TL-11 box in the basement bay. I called Silverleaf for help but they said their system doesn't actually read the monitors but does let the info from the monitors to be read on their system.

I will order a couple new monitors. Anyone have any tricks on removing the wet bay panel? 

[Eric Maclean]

Steve
The wet wall in the water bay on may of these coaches were made of a vinyl coated particle board which water deteriorated requiring replacement with some other material .later Beaver used stainless steel for the wall material.
Many of us here on the form have had the wet wall out and redesign it so it could be removed more easily some have even put hidges on a section so you can see or work in behindvthe wall without removing it.
It might be worth considering if you have to take it out.
If yours has the water pump mounted in a small cabinet on the back driver side bay wall you may find that panel inside the cabinet can be removed to gain access but it's a tight squeeze.
On some coaches you can remove the wet wall without removing the gas struts and others you can't
Most wet walls are held in with trim screwed are the perimeter.
The major connections to the wet wall are done with flexible hoses to allow it be pulled out far enough to disconnect .

Hope this helps
Eric

[Steve Hutchins]

Thanks for the info Eric, I have unscrewed the panel and pulled it out a few inches to see where the monitors were.  Will attempt more when I get the new monitors.

Steve

[Bill Lampkin]

While you are back behind the panel, you might want to replace the white flex hoses now before they leak. I replaced all white hoses with SS braided fixture supply hoses from Home Depot. Peace of mind.

[Steve Hutchins]

With the holidays over and back to AZ where the coach is parked,  I finally found time to work on the replacement of the sensors.  I found new ones at:  https://www.nwrvsupply.com/product/setra-systems-pressure-transducer-2091001pg2m45p1/.

Was able to pull the wet wall out far enough to gain access to the bottom of the holding tanks where the sensors are located.  The sensor on the grey tank had residual in the sensor while the black tank had some obstruction in the fitting before the sensor.

Installed new sensors (old ones are good for backups)  closed up the wet wall....all good!  Sensors are reading 0% with no calibration needed.

Steve