Monitor Panel

[marcum]

The tank monitor panel in my 2006 View reads tank levels incorrectly. I contacted Winnebago and they gave me instructions on adjusting the potentiometers on the printed circuit board to correct the problem. What I found was that instead of pots, fixed resisters had been installed. Winnebago is unable to give me the value of the pots and the company that made the panel won't answer my E-Mails. For the record, this system senses tank levels without the use of probs. Does anyone know the value of these pots or where I can find out?

[Clay L]

Originally Posted by marcum

The tank monitor panel in my 2006 View reads tank levels incorrectly. I contacted Winnebago and they gave me instructions on adjusting the potentiometers on the printed circuit board to correct the problem. What I found was that instead of pots, fixed resisters had been installed. Winnebago is unable to give me the value of the pots and the company that made the panel won't answer my E-Mails. For the record, this system senses tank levels without the use of probs. Does anyone know the value of these pots or where I can find out?

The old through wall sensor system had pots. The new TrueLevel doesn't (except for the propane which uses the same old sensor).
In any case a pot won't help. The sensors (Mirus detector cell) on the side of the tanks are active devices - there are integrated circuits in those black squares - and act like on off switches. As each cell senses liquid it will turn on and the circuit board/display panel sees a specific voltage and lights an LED. Changing the voltage level sensed by the board won't change the fact that the sensor is detecting moisture in the gunk on the tank walls and turning on. That gunk is what is causing the gauge to read fluid in the tank when it is empty.

IF your system is reading lower levels than it should - for example 2/3 full when it is full - then you probably have a bad sensor that is on all the time.

If it is reading higher than it should then you need to somehow clean the tank walls. I have made a 90 degree adapter and pressure washed the black tank walls and I would get correct readings for a while then the gunk would build up again and it would start reading full when it was empty.

I have tried all of the remedies posted such as ice in the black water tank, the geo method, detergent, TSP, etc, etc, and nothing helps.

Note that I don't have a flushing system built in as many people do. Regular use of a flushing system seems to be the only thing that actually works.

There are other systems out there such as the popular SeeLevel but they also have problems when the gunk builds up. The SeeLevel system discusses it in their manuals. Their system doesn't indicate incorrect levels though, it just stops indicating.

[marcum]

Thank's Clay. I won't waste any more time looking for pots. I wonder why Winnwbago didn't tell me that.

[Clay L]

Originally Posted by marcum

Thank's Clay. I won't waste any more time looking for pots. I wonder why Winnwbago didn't tell me that.

I suspect he was thinking of the old system and didn't realize you had the new one.

[marvymaury]

I have a 2006 29R sightseer with problems identical to what you replied to. The 1/3 level black tank intermittment but can be made to work for a short time by using a wand to clean the tank. On this trip the 2/3 & full lights simply stopped working the 1/3 continues intermittent. Do you think this is a buildup of gunk in the tank or is the system burned out a board or whatever. Have you found any chemical to put in the tank to clean out the gunk?
Thanks

[Clay L]

Originally Posted by marvymaury

I have a 2006 29R sightseer with problems identical to what you replied to. The 1/3 level black tank intermittment but can be made to work for a short time by using a wand to clean the tank. On this trip the 2/3 & full lights simply stopped working the 1/3 continues intermittent. Do you think this is a buildup of gunk in the tank or is the system burned out a board or whatever. Have you found any chemical to put in the tank to clean out the gunk?
Thanks

Do the 2/3 and full LEDs stay lit all the time or not light at all?

If they stay lit all the time then they are probably sensing gunk on the tank walls.

If they don't light at all then there is another issue.
The sensors are like switches in series. If all of the switches are open and any of the sensors closes, the 1/3 LED will light.
The circuit assumes that the first sensor that closes is the 1/3 sensor. When everything is working that is a good assumption but if the 1/3 and 2/3 sensors fail and the liquid level gets high enough to activate the full sensor then the 1/3 LED will light. If I understood what you wrote that is what might be happening.

I have never found anything that will keep the tank walls clean enough for the system to work right. Over the years I have tried all the fixes posted including the geo method, ice cubes, etc, etc, etc.

Flushing after every dump is the only thing that seems to help.

[marvymaury]

Originally Posted by Clay L

Do the 2/3 and full LEDs stay lit all the time or not light at all?

If they stay lit all the time then they are probably sensing gunk on the tank walls.

If they don't light at all then there is another issue.
The sensors are like switches in series. If all of the switches are open and any of the sensors closes, the 1/3 LED will light.
The circuit assumes that the first sensor that closes is the 1/3 sensor. When everything is working that is a good assumption but if the 1/3 and 2/3 sensors fail and the liquid level gets high enough to activate the full sensor then the 1/3 LED will light. If I understood what you wrote that is what might be happening.

I have never found anything that will keep the tank walls clean enough for the system to work right. Over the years I have tried all the fixes posted including the geo method, ice cubes, etc, etc, etc.

Flushing after every dump is the only thing that seems to help.

Thanks Clay
The 2/3 & full lights do not light up at all. I filled the tank, I could see the water in the commode, and neither the 2/3 or full lit up. However the 1/3 light seemed to work ie it went out when the tank was drained.
Does this sound like a board fault or maybe one or both sensors went out. If the 2/3 sensor blew how would it affect the full?
Thanks
marvymaury

[Clay L]

If any one sensor fails open the full LED won't light when the tank is full. If any two sensors fail open the only LED that will light when the tank is full is the 1/3 one.

The level that causes the 1/3 LED to light is a function of which two sensors fail.
The 1/3 LED will light when the remaining good sensor sees liquid.
For example:
If the full sensor is good the 1/3 LED will light when the tank is full.
If the 2/3 sensor is good the 1/3 LED will light when the tank is 2/3 full.
If the 1/3 sensor is good the 1/3 LED will light when the tank is 1/3 full.

If any sensor fails closed then the 1/3 LED will always be lit. If any two sensors fail closed then the 1/3 and 2/3 LEDs will always be lit. This isn't what you are seeing.

The display board uses an LM339 Low Power Low Offset Voltage Quad Comparator IC to sense the voltage change when a sensor closes or opens and turns the proper LEDs on the display board on or off .

It would seem that you could have a problem with either a couple of bad sensors or a bad display board.
You could narrow it down by checking the voltage on the wire going from the sensor string back to the display board and seeing how the voltage changes as the liquid level go up. The voltage should drop some as each sensor closes. If you see three distinct drops as the level goes past each sensor then I would think the board is bad.

Before I did anything though I would unplug and re-plug the connectors on the board and at the tank to make sure the connections are good.

Lichtsinn Motors, a Winnebago dealer a couple of miles from the factory is a good place to buy the sensors or board.

[dagray]

I have that same system and have tried everything. I think something wrong with the circut board. If it does appear to be working and reads maybe 1/3 full when you know it is empty, you turn on the hot water heater and the whole board will show full. I just gave up on it.

[Clay L]

Originally Posted by dagray

I have that same system and have tried everything. I think something wrong with the circut board. If it does appear to be working and reads maybe 1/3 full when you know it is empty, you turn on the hot water heater and the whole board will show full. I just gave up on it.

Mine works great on the fresh water tank and sort of works on the gray water tank. It shows 2/3 full when empty then when the tank gets close to full then reads full.

The black tank reads full all of the time. I have pressure washed the black tank walls through the toilet and get a correct display for a few dumps and then it goes back to full all of the time.
Too much crud containing water builds up on the tank walls and fakes the system out.