Tank gauges

JBE-Dad · 06-17-2012, 05:43 PM

This past week I realized my tank gauge monitor doesn't seem to be working correctly. When I hit the button to test the levels of the tanks all the lights light up showing everything is full. I noticed this at the start of my trip knowing for sure that my black and gray tanks are empty (showed that both the gray and galley tank was full). Battery level lights seem to be working fine. After flushing the tanks out real good yesterday all the lights still coming on showing everything is full.

Any ideas???

2008 Ford F350
2009 Cougar 293SAB

chuck&gail · 06-17-2012, 07:07 PM

Well usually flushing doesn't help. You can try this. Dump, then add three gallons of water in each tank, along with a cup of dishwashing liquid, and a cup of water softener like Calgon. In black tank add several bags of cubed ice (never could get cubes into gray tank). Then go for a ride on a curvy road for half an hour. Stop and dump, then rinse. That often works.

Me I gave up on the stupid gauges. If it comes up in shower, gray is full. If I see it in toilet, black is full. Works for us.

f6bits · 06-17-2012, 07:38 PM

How’s your fresh water gauge? If my black and grey tanks aren’t clean, they read high. Give the Chuck method a try and hopefully that’ll get you headed in the right direction.

Festus2 · 06-17-2012, 08:50 PM

Tank gauges have a mind of their own. For some people, they actually give an accurate readout most of the time. For others, they work intermittently - you never know when they will work. And then we have the last group for whom the gauges seldom, if ever work.
To compound the problem, one or two gauges of the gauges, usually the black and grey tanks, give false readings while the remaining one or two appear to be accurate.
They are not overly dependable and many people fall back on the fail safe method employed by Chuck and Gail.
There are a variety of tactics used to keep your black and grey tanks clean and relatively "fresh-smelling". What works for one doesn't seem to work for another - it is a puzzle. These methods have been posted and discussed here many times so if you try one and it works for you - keep doing it.

happytrails · 07-02-2012, 06:32 AM

Quote:

Originally Posted by chuck&gail

Me I gave up on the stupid gauges. If it comes up in shower, gray is full. If I see it in toilet, black is full. Works for us.

Our black tank came from the dealer not working and we used this method too. It's the most accurate too because when it's full, you WILL know it.

Of course if you are dry camping it could be quite the surprise when you have no place to dump. At least in the black tank you can look down the bowl and see it. The gray tanks are a bit harder.

rhagfo · 07-02-2012, 04:18 PM

Well i have used the detergent ice and softener method on our Black tank. First time I hooked it up the pipe was half full with "Stuff" (dried luckily). Started with warm water and double dose of digester and then lots of water. We were at a full hookup, so I did that about three times over the three days we were there.
Next time out did the detergent, ice and softener and it is much better, will do the next couple of trips just to get good and clean.

Ice in the grey tank, the air vent (if extended to roof) might be an avenue if it doesn't have any big bends on the way to the tank. Might be close to a hand feed job.

Fuzion 322 · 11-23-2012, 01:52 PM

My gauges started doing the same thing to. It happened over night with the camper set up and had not been moved for months.

smiller · 11-23-2012, 03:04 PM

The bottom line is that the typical RV 4-LED level gauges are poorly designed generally unreliable and there's not much you can really do about it. There are any number of home remedies that may or may not cure a problem for a while, but sooner rather then later you will be back where you started. I've stopped playing the game and have been doing a pretty good job of simply estimating what is in the tanks (and it doesn't take much of an estimating job to be better than those useless gauges.) If that doesn't work for me I then will invest in one of the better aftermarket alternatives, which is the only real solution.

ktmracer · 11-23-2012, 08:15 PM

as mentioned factory tank sensors are notoriously unreliable because of the very poor design. other than going to external sensors, replacing the factory sensors with Horst miracle probes is IMHO the best way to get a decent set of reliable probes that with a little care (good flushing) will read reliably and consistently. If you have decent access to the tanks, swapping out the factory probes for horst miracle probes is a very simple job, the fit into the same size hole as factory probes. If the factory probes are spin welded in, simply drill a new hole near the existing sensor and swap the leads over.

Ayotte · 11-25-2012, 06:31 AM

Has anyone tried changing the sensor probes to the (Horst Miracle Probes) They advertise that they will solve all your problems.

geo · 11-26-2012, 03:15 PM

If you like projects and don't mind crawling under the RV, check out the SeeLevel tank sensors. (Just web search "SeeLevel"). The sensors are applied to the outside of the tank, are accurate, and can never be fouled by tank contents. The sensors are easy to hook up and configure. The sensors work on an induction method that senses water through the tank wall. The gauges give a percentage "full" reading rather than a light for thirds.

Disclaimer! I am not associated with SeeLevel in any way, except I am a customer and will have them installed on Beauty2.

Ron

azlee56 · 11-26-2012, 03:32 PM

I was going to tell you and haven't had a chance (but I am taking time now) to tell you when the BF and I went to NASCAR I dumped the dawn and the downy down the toilet and bathroom sink to get those sensors clean. I had hoped that. I know the black that normally always shows full was truly full and I said lets let it slop around all the way home (for all tanks). I was pleased at least it cleaned it to where it will 2/3s full now. But what I have to ask you is does that treatment (the way I did it) always make your black water really smelly (even after you dump)!? I cracked up and said maybe it loosened up all kinds of crap! (literally). I will try it again to see if it gets cleaner.

Out of curiousity where and how does these sensors work. Do they float? are they on the wall of the tank?

questions, questions.

geo · 11-29-2012, 08:21 AM

Azlee56 -

I'm not a big fan of dumping bleach or detergent down into the tanks. I know others would disagree with me and have had excellent results with these items cleaning their tanks. As stated, I'm not a big fan.

From your description, it sounds like you might have a black tank build-up. The Dawn and Downy might have very well helped "peel back some covering layers" to get to some decomposing areas. Based upon that assumption, now that you have exposed the "inside" within the black tank, you shouldn't let it dry and crust over. (Yes, there are assumptions here!) Check at the store and see if you can get some "Washing Soda". Not Baking Soda - Washing Soda back in the cleaners/detergents. If not, look in the same area for "Calgon". Washing soda is Sodium Carbonate. Omitting all the chemistry, sodium carbonate is the majority ingredient in the "OxyPower" products. Sodium carbonate is also a major ingredient of Downy and Dawn. (You can also do a search for my post on Sodium Carbonate from a couple of years ago.)

Now, try this. Put maybe 4 gallons of very warm water down the toilet. Add another gallon of warm water that has at least two cups of Sodium Carbonate dissolved in it. If you do this procedure in the afternoon, wait until next morning for this next step. That way the warm water will have time to soak into the "mound" and cool down. Warning: the tank might get odorous from this treatment at this point! Hitch up the RV and be ready to drive off (before the ice melts). Get maybe 3, better 4, bags of ice and make sure the chunks of ice are broken up enough to pass down the toilet without damaging the seal. (Don't break the ice chunks up inside the toilet bowl!) Dump the ice down the toilet. Now take a nice drive out to see the Arizona desert! Make sure you have a somewhat twisty road, through a few hills or down a couple of arroyos, and a few bumps would help also.

After an hour or so of driving, head back to the RV Dump Station. Do you have a black tank flush? If you do, carefully (!) put some additional water into the black tank with the flush. Don't overfill!

Then leave the black tank flush running and dump the black tank. If you have a clear section of dump pipe, you should be able to monitor if you have "old crud" coming out of the tank. If you do, you will have to decide if you "got it all out" or if you might need to repeat the procedure.

The standard tank sensors are fairly simple. They are basically exposed sensors inside the tank - a metal nub that extends into the tank from the tank wall connector. As the tank fills with fluid, the sensors are "shorted out" by the fluid, and the monitor panel shows this "short" as a lit LED indicating fluid level. The problem comes from "stuff" being caught on these sensors. The "stuff" causes a false reading. It can either "connect" to the fluid below, or it can actually insulate the sensor so it doesn't "sense" the fluid level!

Interestingly enough, adding sodium carbonate to a "clean" tank will also cause a false reading. The sodium carbonate will decrease the surface tension on the top of the fluid such that the fluid will "creep" up the sides of the tank. Thus the tank will appear to be more full than it actually is.

Most stock RV sensors seem to be a type sold by KIB Electronics. You might find the KIB Electronics website interesting, especially the FAQ that describes how to test the tank system. (However the test resistor should be 43 kilo-ohms, not kilohm. That's 43,000 ohms.)

http://www.kibenterprises.com/faq.html

Ron

smiller · 11-29-2012, 09:06 AM

Those are some great tips but are a lot of effort to go through every time the tank sensors get funny, which in the case of the typical OEM sensors will be pretty often. Perhaps better to spend the money once to upgrade than spend all the time it will take to keep the original units working.

geo · 11-29-2012, 03:38 PM

Smiller -

You are correct. However, it sounds like Azlee56's black tank problem stems from a black tank that hasn't been dumped and allowed to dry. If my memory serves me, I believe she purchased a previously owned RV, so she might be dealing with the previous owner's ... ah, how do I say this ... "stuff"! I think once she gets the tanks cleaned, she probably won't have further problems. She's been around the Forum long enough to see most of our rants, er, advice. I'm thinking she might have more than half a tank of "stuff" that needs to be "evacuated".

Ron

Bushman512000 · 11-30-2012, 06:17 AM

close Your eyes.I never look at the junk I do how ever use Ox-adoll soap I mix it first to desolve dump a 1/2 gallon -1/2 cup of soap to each tank and no smell that is the best think I found yet and I use some snuggle fab.softner 1/2 cup to a gallon of water I think that helps to keep the tanks slick for draining and no waste build up..Bushman try and You may find it works as I did...

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