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 12/17/2003 2:02 PM
Hello, I know this has been on here many times - questions concerning the failure of the holding tank sensors to function properly. The black water readout is always in the red zone (full) when fully emptied. I have used the hose extension that has the "spinner" at the end. Did not do the trick. Used the chemical that is suppose to clean everything after sitting and being swirled by driving down the road. No luck. I can see the screws on the ourside of the tank that hold the wires in place. There are little tabs at the ends of the wires. Some look like they may have some corrosion on them. Not sure what would happen if I remove the screws and seek to clean the connectors at the ends of the wires (4 wires). I don't want something to drop down inside the tank when I remove the screws that hold the wires. This is a '99 Itasca Suncruiser 35C. If anyone has had experience and would provide an answer or suggestion, it would be appreciated. I thank you in advance.
Tom Colladay Big Rapids, Michigan colladat@ferris.edu
Wintering at Gulf Shores, AL

Happy Travels, Tom Colladay, Home State: Tennessee '04 Winnebago Journey DP and '99 Malibu towed.
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 12/17/2003 7:52 PM
Tom, I'm afraid you're finding out there is "NO" sure fire method of keeping these contacts clean and working accurate. I'm a fulltimer and on our 7th RV in 25 years, outside of maybe 1 of them none of the sensors worked accurately after a few months. I too have tried everything advertised to make them read better but nothing works like advertised. What I do is watch the water reaction after a few days when I think it is getting near full and ready to be dumped it sort of "burps", that's my que to empty it. I quit trying to leave it up to the faulty sensors.

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 12/18/2003 3:14 AM
Hi Tom. My experience is like Neil stated. Most RVs are made with "contact" sensors in the tanks and the crud in there fouls the sensors. I "fixed" my sensors by putting on a system that doesn't contact the liquids in the tanks. Go to www.rvgauge.com for a description. A system costs close to $300. Fortunately, you can use the existing wiring. If you don't want to spend that much, you'll have to rember to "count the days" after dumping! Regards,
Fred White Polk City, FL

Regards, Fred White Polk City, FL
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 12/18/2003 6:49 AM
I agree that everyone has the same problem. It seems that you have done all of the normal things to clear the sensors without going into the systems components.
However, you might try to fill the tank with ice and drive the unit letting the ice rub against the tank walls and senors to see if it lossens up the material causing the failure.
My unit is only 6 months old and I had the problem. I tried the ice approach and it worked. In your case the RV is a little older and materials may be badly caked on the senors. You may want to try adding a little chemical (deluted bleach also works) first to soften up the materials.
Happy Trails Al Packwood
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 12/18/2003 7:07 AM
Perhaps I missed it, but I don't recall any mention of a flushing device installed on the tank. Whatever choice you make--from ice cube therapy to Fred White's new sensor system--if you don't have a permanent flush system on the black tank, you can purchase a system from any camping store and either have them install it or install it yourself. I've found that the use of this system each time you dump will go a long way to keeping the sensors reasonably clean and usable. Dutch Hebron, MD Polk City, FL
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 12/18/2003 8:18 AM
If there were material caked on your sensors in sufficient quantity to disturb their electrical conductivity, the little red lights would be stuck OFF, not stuck ON. (This assumes that there is not something wrong with your wiring.)
You need to clean off the conductive material on the tank wall BETWEEN the sensors. Sometimes, just allowing the tank to dry a bit before taking a reading will allow the red lights to go out. To remove sticky, waxy, greasy build up, you need HEAT not cold. You need detergent which will separate the grime from the wall of the tank. Driving around with plain water in the tank may do the job as well as anything else. Adding detergent (not soap) to the tank before driving around may help. Some of the tank chemicals provide detergent action for just this purpose.
The probability of floating ice cubes hitting the gummed up area in sufficient number and frequency to dislodge it is about the same as winning the lottery. Cold makes gummy build up harder to remove. Since there are people who report that plain water "works for them", I assume that water plus ice cubes, Kool-Aid, lemon juice, vinegar, or what have you, would also work.
If you are stationary, a calendar would be a whole lot easier to work with.

2004 Brave
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 12/18/2003 8:39 AM
RAS - I haven't experienced sensor lights not lighting because the sensors are "caked", but agree that the problem of them being continuously lit is usually caused by scum forming a bridge between the contacts and providing a continuous electrical path, just like the wastewater does when it reaches that level. This causes the sensor to always read “ON”, indicating a waste level that's false. On some tanks it's not difficult to remove the offending sensor (empty the tank first), which may be one or two screws, and clean them thoroughly. But, it's probably only a matter of time before they're re-coated. Good luck. - Dave This message was edited by Dave_Peters on 12-18-03 @ 9:44 AM

Webmaster Rvamerica.com Support@rvamerica.com
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 12/19/2003 4:13 AM
I installed a spray nozzle above the sensorsand a hose connection for the nozzle in the utility bay. Our sensors work OK. However if one or more hang up (light) when I know they should not, Then I flush the tank with the Spray sytem after the next dumping. It has cleared the sensors everytime. We have had this MH for almost 4 years and it has 86,000 mileson it. The sensors still work fine BUT at times one or more will hang up. The cost of the hose, nozzle and other fittings was about $20. Jim on 'Monkey Business
PS Always use plenty of water in the black tank. More water is better. Spic-N-Span does a good job when cleaning the tank.
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 12/19/2003 12:51 PM
Simply from the response, we know we share a problem of keeping those leads clean so they'll give an honest reading. I've tried the ice, and I've used the built-in spray system in three different coaches. When attending an RV seminar a couple of years ago, I learned about retricting all soaps and detergents to AVOID "anti-bacterial" types and to sometimes add a cup of Dawn dish soap to a full tank as you drive off on a bumpy road. Whenever I try this, it seems to work. And, yes, we carefully watch what we flush to avoid anything caustic or anything that would kill bacteria. If we follow that seminar speaker, we're supposed to love bacteria. Bob McNabb 2004 Holiday Rambler Scepter DP/3 slides 1998 Saturn toad/BrakeBuddy

Bob McNabb Sunny San Diego
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 12/19/2003 3:55 PM
[quote] Some look like they may have some corrosion on them. Not sure what would happen if I remove the screws and seek to clean the connectors at the ends of the wires (4 wires). [/quote]
If the wires were not making contact with the sensors there would be no current flow, and the lights would never light. The problem is stuff inside of the tanks and I too am a fulltimer who just doesn't worry about it, but dumps regularly. But at a seminar at Lazy Days RV in Tampa they suggested that the cleaner TSP mixed with 5 gallons of water and dumped into each tank will do the job and will not hurt the seals. I don't know as I have not tried this one, but TSP is what is used to clean walls for painting so I know that it is a good cleaner. Good luck!
Good Travelin !..............Kirk URL:www.1tree.net/adventure/

Travelin Man
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