monitor panel black tank display

The sensors in the black water tank are quite often on after using then dumping the tank. They need to be washed off. I use a hose attachment that has wand and a spins water out to clean tank. There are other methods, I am sure you will get more responses.

Monitor your water use in both waste tanks and forget the sensors. Dump and fill whenever available and move on.

Google the Geo Method. I do this a few times a year (more often when I'm on the road).

The spinner type of wand that Ava uses is prone to the spinner breaking off and getting lodged in the dump valves. I'd use one with no moving parts like this.

Wet paper and gunk stay on the probes even after you empty the tank, so it shows "full" when it's not. New probes or not.

If you have a black tank sprayer, that can sometimes get it to read better. If you are in storage for a while and the paper and gunk dries, that can show your tank is not as full as before even though you have done nothing.

Best thing is to learn from experience how many days it takes to really fill the black tank (you can tell at the toilet), and mostly ignore the monitor. Keep track of days since the last dump. It is best to get it near full before dumping of course, so it flushes like it means it.

The only way I have gotten them to work (for a little while) is to make a wand that has a couple of 1/8" holes. With CG water pressure at full blast the stream is extremely strong and blasts away all the gunk on and around the probes.

I tried cleaners and the famed Geo method (which didn't work) and nothing did the job better.

I installed NEW Horst Miracle probes. THEY ARE NOT FULL OF GUNK but brand new.

I assume (dangerous, I know) by your last post you have not put anything in the black tank since you changed the probes, correct? This pretty much eliminates them as the problem. I would look at as much of the sensor wiring as you can see to make sure nothing is chafed and/or shorted to the frame or another wire. Also, something may have failed in the "red thing" which is probably the electronic circuit which reads the probes and lights the lights. I don't know how to test this or where you could get another one. Maybe someone else can help you with that. You could also add something like the SeeLevel tank sensor system which is supposed to be pretty accurate and trouble proof but that is $$$.

Hope this helps.

Ken

There are replacements for the "red thing" if you buy the full KIB repair kit which includes a new monitor plus the wiring. The wiring from each of the probes goes to the "red thing" which doesn't do anything electrical I think other than convey the grounds back to the monitor. I am guessing but think perhaps that the four probe wires are just grounds which complete the circuit which causes the idiot lights to light and the 12VDC is supplied to the panel from elsewhere. The wires run along a long loom from front to rear of my 5ver and enter somewhere in the back with the wires going to the electrical box. The wiring is what it is as it is pretty much hard (if not impossible) to trace. One symptom is that ALL FOUR idiot lights are lit so that would mean the false ground is not where the wires come out of the probes otherwise only one would light an idiot light if only one were damaged. It is possible that the "red thing" is buggered as I have no idea its function but not sure how it could produce a false ground signal even if all the wires from the probes were touching inside. A replacement monitor which is plug and play is $27 and I am leaning that way as the wiring is just too darn hard to chase.

The probes are positive to battery.

"The 3 probes on the left are placed so that they sense the different water levels. Electrical current flows between the metal tips of probes connected to a PLUS (+) of a battery and the one on the right, which is connected to the MINUS (-) through the liquid. This current lights up the LEDs."

More info here- scroll all the way through for full explanations:

http://www.rvprobes.com/howitworks.html

I can't tell from the OP and this linked info if the new protected probes will read right if the tank has not been fully cleaned out. I would try to clean it out. Even a garden hose with nozzle set to a good spray shoved down the toilet would help.

Wow. Thanks for the post BFL13. I had made some (hate using the word) assumptions on how the probes worked. The webpage you sent cleared that up. Will have to check voltage on the wires to see if they are connected correctly I guess. I did drain the tank and the probes are new. I did a back flush using the hose in the clear elbow gizmo but the bend is sharp going up to the black tank so am not sure if this fully cleaned the thing. I have a wand and will stick it down the toilet and see if that produces any results.