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Topic: 2002 U320...list black tank readout not displaying... (Read 668 times) previous topic - next topic

2002 U320...list black tank readout not displaying...

The black tank was showing normally last week (along with all the others) on the Javelina display panel. Though now the black tank doesn't register any level at all; however, both fresh an grey water and fresh still are function normally.   
So I wonder if there are tank wall sensors that fell off - really, all of them? No reading at any level.
I have caused no mechanical disruptions lately because we have been parked the whole time. I even flushed the black tank several times with forceful water through the stool.
Hum...not sure where to begin looking.  Broken connection? Suggestions??
Jim



Jim Frerichs
2002 U320 42'

Re: 2002 U320...list black tank readout not displaying...

Reply #1 –
If this is a Javalina system, the tank sensors are pressure transducers screwed into fittings on the plumbing.  They read the hydrostatic pressure of the tank itself and output voltage to the Javalina computer that translates that to the calibrated tank level.  They are not tape-like sensors mounted on the tanks like the SeeLevel ones.

To get to the black (and grey) tank sensors, you have to disassemble the utility bay of the coach.  The sensors are behind it.  In the attached photo, you will see a white hex-nut device with black cap that has wires going from it on the left and on the right sides in the photo.  Those are your tank sensors.  DO NOT REMOVE THEM UNLESS THE TANKS ARE COMPLETELY EMPTY 

There are no replacement Javalina sensors available.  Most go with a complete SeeLevel system as an upgrade when failure occurs.
Learn every day, but especially from the experiences of others. It's cheaper!  - John C. Bogle

2000 U320 36' non-slide / WildEBeest Rescue
2003 U320

Re: 2002 U320...list black tank readout not displaying...

Reply #2 –
Michelle,
I was afraid of that. Guess I will tap on it to see if it will come out of its funk. On a 2002 where night this pressure sensor be located besides externally somewhere in the tank plumbing? It appears buried in the coach.
Jim
Jim Frerichs
2002 U320 42'

Re: 2002 U320...list black tank readout not displaying...

Reply #3 –
Quote from: Jim Frerichs –
Michelle,
I was afraid of that. Guess I will tap on it to see if it will come out of its funk. On a 2002 where night this pressure sensor be located besides externally somewhere in the tank plumbing? It appears buried in the coach.
Jim

It is buried in the coach.  As I mentioned in my earlier reply, they are behind the back wall of the utility bay where the dump valve handles, faucet, cable outlets, etc. are.  You have to disassemble all that attached stuff, cut the caulking on the panels, and remove the back wall to get to it.  After you remove all of that and gain access, the photo I posted is what you will see.
Learn every day, but especially from the experiences of others. It's cheaper!  - John C. Bogle

2000 U320 36' non-slide / WildEBeest Rescue
2003 U320

Re: 2002 U320...list black tank readout not displaying...

Reply #4 –
My black tank sensor is located in the water manifold bay on the passenger side. The sensor is actually fairly easy to see and access without taking much out.

The grey tank sensor is another story!
2002 U270 34' Build 5953
Cummings ISL400HP
3410 Floor Plan
Longview, TX

Re: 2002 U320...list black tank readout not displaying...

Reply #5 –
You might get lucky and take it out and clean it, but probably not. I would try it first.
previous 1984 35 ft ORED 250 HP 3208 Cat       
previous 1998 40 ft U295 CAI 325 hp Cummins
previous 2003 40 Ft u320 build #6140 450 Cummins M11.                                                         
1999 Mazda Miata
Ron, Nancy, Tipper the cat, Max The dog
1997 U 270 36 ft build number 5174 8.3 Cummins

Re: 2002 U320...list black tank readout not displaying...

Reply #6 –
Quote from: Eric & Alena + 3 –
My black tank sensor is located in the water manifold bay on the passenger side. The sensor is actually fairly easy to see and access without taking much out.


So in your '02 it's in the same bay as the fresh water sensor? 

That IS a lot more convenient than in an '03.
Learn every day, but especially from the experiences of others. It's cheaper!  - John C. Bogle

2000 U320 36' non-slide / WildEBeest Rescue
2003 U320

Re: 2002 U320...list black tank readout not displaying...

Reply #7 –
I think that it depends on the layout of the coach. Most have both sensors on the drivers side behind the wall like Michelle said.
previous 1984 35 ft ORED 250 HP 3208 Cat       
previous 1998 40 ft U295 CAI 325 hp Cummins
previous 2003 40 Ft u320 build #6140 450 Cummins M11.                                                         
1999 Mazda Miata
Ron, Nancy, Tipper the cat, Max The dog
1997 U 270 36 ft build number 5174 8.3 Cummins

Re: 2002 U320...list black tank readout not displaying...

Reply #8 –
Wow, good answers from you guys...thank you! I will search for the sensor in the daylight tomorrow. Wish me luck that it is just clogged up.
Jim
Jim Frerichs
2002 U320 42'

Re: 2002 U320...list black tank readout not displaying...

Reply #9 –
Jim, the black tank sensor seems to be an earlier victim to sludge than the others.  It my be possible to remove it and clean it and have it regain function.  I looked at mine, pitched it, plugged the hole and put in a SeeLevel system.  More reliable, more accurate.
Roger Engdahl and Susan Green
2001 U320 3610 #5879 (Home2) - 2014 Jeep Cherokee or 2018 F150
Hastings, MN

Re: 2002 U320...list black tank readout not displaying...

Reply #10 –
I don't have the coach at the house, but you can see the fresh water sensor in this picture and the black tank sensor is behind the white door. You would need to remove just the carpet cover around the water manifold to access the valve and sensor.
2002 U270 34' Build 5953
Cummings ISL400HP
3410 Floor Plan
Longview, TX

Re: 2002 U320...list black tank readout not displaying...

Reply #11 –
I took a picture through the white access door in my previous post. You can see the black tank sending unit. I hope this helps.
2002 U270 34' Build 5953
Cummings ISL400HP
3410 Floor Plan
Longview, TX