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kevinmlamb · 08-09-2016, 08:58 AM

Just returned from a 4-night weekend with water and electric, but no waste hookup. The lights on the monitor panel showed the gray water tank filling steadily, but the black water light was green all weekend. On literally the last flush of the weekend, the toilet backed up...black water tank full. But the light was still green. Fresh water, gray water, and battery lights all worked just fine. Fortunately, there was a dump nearby, so no worries there. Got home and filled the black water tank again halfway from a hose, added ice cubes (as I'd once read to do here on the forums), and drove around to see if anything dislodged that might be causing the malfunction. Dumped again. Refilled again. No dice. The light's just not registering. Any thoughts on a possible fix would be appreciated.

israndy · 08-09-2016, 09:20 AM

Are you having trouble with the MicroPulse monitor panel?

You can try to isolate the sensors from the panel, just pull it out of the wall and trade the black wire for any of the other tanks wires and see if the problem follows the wire. You may just need a new sensor:

-Randy

xrvr · 08-09-2016, 10:43 AM

You'll learn not to trust the monitors.

israndy · 08-10-2016, 07:23 AM

Well, trust with verify...

-Randy

SafariSarah · 08-10-2016, 11:30 AM

try driving around with some vinegar in the tank to clean the sensor?

cazual6 · 08-10-2016, 11:37 AM

I had that same problem for a little bit. I didn't do the ice, I just kept cleaning and cleaning it with the inlet. I didn't know about this forum back then, the dealer told me, it was a piece of regular toilet paper when I took it, again, I was new and didn't know about RV toilet paper. I prefer cottonelle, they are so soft, but not ideal for septic or RV use.

Regular toilet paper can sometimes get lodged in and it is very tricky to get rid of especially when it hits the right spot on the sensor I guess.

To this day, knocking on wood, my sensors have been 100% accurate.

TBRich · 08-10-2016, 11:44 AM

We just had to have the black tank sensor replaced on our 2006 Bambi...first it flashed red (full) when empty then quit registering all together...the sensor had failed...

Konbe · 08-10-2016, 12:49 PM

A year ago after a 2000 mile trip, we returned home with a black tank monitor light flashing red even when the tank was completely empty. I did two treatments with the GEO method of tank cleansing, allowing the tank to sit for several days with the treatment in the tank which was full as possible. I figured that if we had to take the trailer to have the sensor serviced, at least everything would be really clean! I found this method to be very helpful, so check it out. http://www.irv2.com/forums/f53/the-g...nce-17957.html After the second dump the sensor began to work again, so probably the treatment made the difference. We have continued to use the GEO method for the tank ever since.

We just returned from a similar two thousand mile trip and are happy to report no problems at any point at all this year.

CharlieSK · 09-27-2016, 05:46 AM

On a recent trip, black and gray were working fine, we dumped and moved to a state park with only electric. First time we checked our tanks, both the black and gray monitors were to responding. Tried a couple of things based on recommendations on this forum - still not working. Once we returned home, I purchased a 25 foot phone wire and connected to the black sensor and then ran along the outside of the Airstream, through the door to the MicroPulse Monitor Panel and plugged into black. The monitor then reported the status of the black tank. So there is an issue with the black wire; either the end connections or somewhere in the wire. Have not been able to run the same test for the gray tank (started to rain) but plan to do that soon.

israndy · 09-27-2016, 10:58 PM

Many times the problem with the wire is the connector at the end. If you have tools for replacing a phone connector on the end of the wire you may not have to run a new length of wire to repair your issue. You can get the tool at places like RadioShack with connectors. Probably under 25 bucks. On mine the wire has no slack, completely taught running across the top of the basement. If mine is a wire issue I will have to rerun.

-Randy

PatandLane · 09-28-2016, 03:19 PM

Just today discovered a similar incorrect indication on the status monitor of our 2007 Classic Limited. Empty blackwater tank shows full. Thanks, Randy, for the troubleshooting tip. Will most likely try to swap wires tomorrow to isolate the problem. Please tell me how to locate the sensor in case I have to check it out.

Wingeezer · 09-28-2016, 03:50 PM

I have never had much luck with the level monitoring system and don't really bother about it any more.

We don't usually need to be concerned anyway as mostly we are on full hookups.

But if we have no sewer connection, as does happen at times, then my highly technical substitute way to monitor the black tank level is to look into the toilet bowl with the valve open!

I have an equally sophisticated way to monitor the grey water tank level - I check to see if water is backing up in the shower pan!

If we do camp with no sewer hookup, it is never more than a week or two and as we only use the toilet to pee in, black water levels are never really an issue - even when I use the toilet to dump sink water in order to save grey tank capacity.

I have a few other things we do to save our grey water tank capacity, so that usually is not an issue either.

I guess if one does a lot of boon docking the situation would be different.

Brian.

PS - I do however carry telephone jack tips and the tool to install them - but that is mainly to help if we have problems with the leads from teh thermostat to the AC unit. I don't have any good work-arounds for that situation!

westcoastas · 09-28-2016, 05:28 PM

Get a flashlight with a wrist loop at the end. Use the loop and shine the light. Forget the sensor.

KJRitchie · 09-28-2016, 05:58 PM

Fill the tank with about 10 gallons of water and some laundry detergent. Try towing the AS stream to stir things up. Let the water sit for 24 hours or more. Then dump and recalibrate the black tank.

Buy an inline water meter that you can attach on your water hose. On my 25fb the leads from the panel join the leads coming up from the tanks by an RJ11 connector. When I calibrate my tanks I disconnect the leads at the connectors of the tanks I don't want to calibrate and I have the trailer just on battery not shore power. Put the monitor in calibration mode then diagnosis mode. The tanks not connected will not light up. Put the calibration into the empty tank mode then fill the black tank with 2-3 gallons of water. Let the water stand for several minutes. Then put calibration into full mode. Fill the tank to 1 or 2 gallons shy of maximum capacity using the water meter to monitor. Let the water sit for several minutes before finishing calibration. Drain out the water and fill at 3 gallon intervals to test the monitor panel. Put the black tank in continuous monitor mode to see how the lights progress up to full.

Kelvin

Rich W · 09-28-2016, 06:57 PM

Quote:

Originally Posted by israndy

Are you having trouble with the MicroPulse monitor panel?

You can try to isolate the sensors from the panel, just pull it out of the wall and trade the black wire for any of the other tanks wires and see if the problem follows the wire. You may just need a new sensor:

-Randy

I don't see any screws, does the bezel just pull / pry off? Any special trick? None of my sensors are working properly, I'd like to swap some of the wires and see if it makes a difference.

CharlieSK · 09-28-2016, 07:55 PM

On the one in our trailer (only difference I see is we have two LP tanks), the top pries off. There is spring clip on the top. On the bottom, there are two plastic tabs on the front face that fit into two holes (short slots) on the bottom. As I recall, it was more difficult the first time and I needed a small, flat screw driver to CAREFULLY pry the top out. Now I am able to just use fingernails. When I reinstalled the last time (yesterday) I had to adjust the spring clip on the top.

Rubygal · 07-11-2020, 04:30 PM

Thanks all. As a new RV'er with an older trailer, I am so glad to find the useful information you all share; especially since the monitor for my black water tank is not registering correctly. Will try some of your ideas.