Monitor Panel Problem

[peholden]

My panel displays the status of the battery, fresh, gray and black water tanks. All indicators are shown as from one to five red lights. One light means the tank is empty, two lights means 1/4 full, etc.,. The five lights (or fewer) light up when the gray water button is pressed or the black water button is pressed and so on.

All functions are working fine, except for the gray water tank. The first light comes on, indicating an empty tank, but that's true even when the tank is certainly nearly full. In other words, the 1/4 and 1/2 and so on lights never come on.

Any ideas about what went wrong and how to fix it would be most welcome.

Thanks, Pete

[peholden]

Thank you DrewE and Dougrainer for your consoling thoughts.

Pete

[dougrainer]

DrewE wrote:
No problems there.

It's rather telling that nobody at all suggested checking whether or not your tank was, in fact, empty; the idea that the gauge lights might actually be working properly didn't occur to any of us, apparently. That should suggest how reliable or unreliable the systems typically are.

To be fair, mine do seem to indicate properly more often than they don't, though not exactly 100% of the time.

I don't think it is telling that nobody suggested his tank might be empty. The OP is HONEST. Most people that pull dumb things never follow up and admit they made a big error. You assume that when they have a problem it is because they have everything in a workable situation.

[DrewE]

No problems there.

It's rather telling that nobody at all suggested checking whether or not your tank was, in fact, empty; the idea that the gauge lights might actually be working properly didn't occur to any of us, apparently. That should suggest how reliable or unreliable the systems typically are.

To be fair, mine do seem to indicate properly more often than they don't, though not exactly 100% of the time.

[peholden]

I am a moron. Yes, I have to confess to all you wonderfully helpful folks that my "problem" was the result of my own stupidity. I had left the dump valve open so the tank was never filling up. Oops.

Sorry, Pete

[BFL13]

Thanks. The "empty" light just means it is not up to the next level where there is a probe. It does not mean actually empty, so I thought it meant there is a bottom probe. Now I see that comes out the same with no bottom probe.
I agree it is way more likely that the ground is lost than to lose all of the individual probe positives.

[DrewE]

BFL13 wrote:

dougrainer wrote:
At the tank probes, there are 5 wires. 4 of those are 1/4-1/2-3/4-Full. The 5th is the ground wire connection at the bottom of the tank next to the 1/4 probe. The ground wire is not connected to the frame ground or the tank. Doug

In my post above I thought it was the positive wires because he got the one light saying empty. How can he get the one light if there is no ground?

Many of these displays light up the empty light anytime the test button is pressed, regardless of what goes on at the probes. The light is just wired directly to the test switch and doesn't show anything at all (other than the display circuit board is on). I know mine is wired that way.

It's possible that there's a problem with the display board if it's not the wiring or probes or resistor pack. That's not as likely, but it can happen from time to time.

[BFL13]

dougrainer wrote:
At the tank probes, there are 5 wires. 4 of those are 1/4-1/2-3/4-Full. The 5th is the ground wire connection at the bottom of the tank next to the 1/4 probe. The ground wire is not connected to the frame ground or the tank. Doug

In my post above I thought it was the positive wires because he got the one light saying empty. How can he get the one light if there is no ground?

[dougrainer]

At the tank probes, there are 5 wires. 4 of those are 1/4-1/2-3/4-Full. The 5th is the ground wire connection at the bottom of the tank next to the 1/4 probe. The ground wire is not connected to the frame ground or the tank. Doug

[Learjet]

drsteve wrote:
Dirty sensors give false readings when the tank is empty. Yours are just not working.

Sounds like a sensor wiring problem.

yes...wiring problem...broken wire or bad connection is most like the problem...I had this once.

I love all the people that chime in with blah blah blah and really no help.... 🙂

[Roger10378]

Several years ago while doing some other work I discovered that the wires on my fresh water tank had been chewed thru. I hadn't noticed that it didn't work because I know they are unreliable.

[drsteve]

Dirty sensors give false readings when the tank is empty. Yours are just not working.

Sounds like a sensor wiring problem.

[camperdave]

Usually they read full when they are not. Yours is backwards. I'd look at the actual wired where they connect to the tank and see if they got pulled off.

[John_Wayne]

Go back to the manual way to read tank levels. If toilet backed up black tank full, water backed up into shower gray tank full.

[peholden]

Thank you, all, for your input.

Pete