Rv tank level monitor panel

[banjoman]

I have a 2001 Roadtrek 190opular. The monitor gauges for the fresh water, black tank, and grey water are not working. The Propane, battery, water heater all seem okay. I would like some advise as what could be the problem. I have checked the the wires at the back of the panel and all connections appear to be OK. How do I go about checking out the panel? I have found units for replacement on the net but don't want to replace if it is a matter of a ground wire or some other simple fix. I can get to the wires a t the back of the panel but I don't know how the face attaches to the wall.
Any help would be greatly appreciated.

Banjoman

[obgraham]

Even if you fix any broken connections, they still will not read accurately much of the time. Just a reality of the RV life.

[ManWonder]

i keep an old broomstick handy to get an accurate check of my tank levels...

[BBQ]

Originally Posted by ManWonder

i keep an old broomstick handy to get an accurate check of my tank levels...

just don't double dip.

[booster]

A lot of us have just upgraded to the Seelevel monitor system that uses external sensors. Not too bad to install, but not really easy either, but can use the existing wiring which really helps. They work well, and the in tank ones never work very well for long.

[avanti]

Originally Posted by booster

A lot of us have just upgraded to the Seelevel monitor system that uses external sensors. Not too bad to install, but not really easy either, but can use the existing wiring which really helps. They work well, and the in tank ones never work very well for long.

The Seelevel sensors do indeed appear to be robust. However, I have been having trouble with the display unit being flakey. I often have to tap on the display in order for all the LED segments to come on. Anybody else see this? Any fix?

[booster]

Originally Posted by avanti

The Seelevel sensors do indeed appear to be robust. However, I have been having trouble with the display unit being flakey. I often have to tap on the display in order for all the LED segments to come on. Anybody else see this? Any fix?

What LED segments are referring to, the ones that create the reading % numbers? That sounds like a loose wire or bad solder joint. Ours has not shown any tendency to do that.

[avanti]

Originally Posted by booster

What LED segments are referring to, the ones that create the reading % numbers? That sounds like a loose wire or bad solder joint. Ours has not shown any tendency to do that.

Yes, several segments of the numeric percentage display randomly fail to light. Enough so such that it can't be read. Tapping it with a finger tends to fix it. Yeah, must be a bad internal connection. The internals are not easy to get at, unfortunately.

[Davydd]

Advanced RV uses barometric sensors. They work very well especially with tanks that are not precisely rectangular. They are able to install custom designed odd shaped tanks to gain more gallon capacity in available space as a result. About the only time they go haywire I've noticed is when you come down off a mountain top but that is only for a short time.

[gregmchugh]

Originally Posted by Davydd

Advanced RV uses barometric sensors. They work very well especially with tanks that are not precisely rectangular. They are able to install custom designed odd shaped tanks to gain more gallon capacity in available space as a result. About the only time they go haywire I've noticed is when you come down off a mountain top but that is only for a short time.

Since you seem to value facts, I would say that they are using a pressure sensor in the bottom of the tank that measures the total of the barometric pressure acting on the surface of the liquid in the tank plus the added pressure due to the weight of the liquid. If it has a problem with rapid changes in barometric pressure in the mountains then it must at some point use some logic to recalibrate itself for the barometric pressure change and restore accurate readings of the level of liquid in the tank. Not sure how it handles the different densities of the water, grey water, and black water but there may not be much difference. I am not inclined to measure the differences myself but it would be a good experiment for an inquisitive student to do for extra credit.

[Davydd]

I don't think it is in the bottom of the tank. You are assuming weight. They replaced one with their newer version under a complimentary upgrade and the tank was not emptied. Do I know what it is and how it works? No. All I know is they said that's how it works. There is nothing I guess to get sludged up and it does seem accurate and reads out in percentages in 1 percent increments and not idiot lights. The accuracy seems steady but there are unexplained changes. My previous two Bs the black tank readings were absolutely worthless. Turning off the water, Opening the flush valve and looking down the hole with a flashlight was more accurate. When water came up the bathroom floor drain one knew to dump the grey water.

I would have not known about the rapid change while descending a mountain had I not come down San Jacinto Mountain in California and having the low water alarm go off when I had about a 60% full tank when I started out. By the time I got to Palm Springs driving in the valley for about 10-20 miles all was OK again.

[BBQ]

.

It would be easier to use ultrasound than to use barometric pressure.


ps. to adjust for changes in altitude, all you need is a second sensor to measure the ambient pressure, just like an airplane's static pitot port.

[avanti]

You can get some interesting technical (and approximate production number) data about ARV systems here:

Advanced RV | SilverLeaf Electronics Technical Resources

If you follow the links, you will get to a simple Kavlico pressure sensor.

I can't imagine that this is doing anything other than measuring head pressure (which implies that it is on the bottom of the tanks). Anything else would require sealed tanks, which I very much doubt.

As far as I know, there are only three systems in common usage:
1) metal contact studs that penetrate the tank. These get dirty and stop working.
2) Density-sensing transduser strips mounted outside the tank. This is what SeeLevel uses.
3) Head pressure sensors at the bottom of the tank. MicroPulse uses this technique.

I am pretty sure that ARV uses #3. If not, I can't think what the alternative might be.

i am guessing that DavyDD's mountain experience had more to do with slope than with barometric pressure.

[gregmchugh]

Here is the pressure sensor ARV uses, could be screwed into the tank anywhere near the bottom of the tank, even on the side of the tank.

Kavlico Tank Sensors | SilverLeaf Electronics Technical Resources

Looks like it is this is the one with more info.

P500

[Davydd]

You guys have done more research than I have.

It works better than my previous Bs with a lot more accuracy so it was nothing I had given a lot of thought. I also know I have had two different installations so don't know what they use.