Holding tank sensors/gauges not working right

[GoldenBoy]

re 2020 Dynamax Force. The holding tank gauges are not showing correct information. about 3 weeks ago I filled the fresh water tank and as it filled the gauge showed the progress, 1/3, 2/3, full. I just returned from a short trip and when I dumped grey tank, black tank and refilled the water tank the grey tank monitor still showed 1/3 full when empty, the black tank showed empty and the water tank gauge showed empty when full. Can someone give me some clue about what might be the problem and how to fix it?
Thanks

[SeaDog]

I think I would start by checking the connections at the tank sensors.

[Oaklevel]

This is fairly common.

Crud gets on the sensors and they do not read correctly. They are not usually the best quality to begin with.

I stopped paying attention to ours years ago.

[itat]

I agree with Oaklevel that the tank level sensors in the grey and black tanks are not very reliable however I use both the Geo Method (Calgon water softener and detergent soap) and RV Digest which seems to clean the sensors fairly well. Occasionally using a degreaser in the tank that your kitchen sink drains to will also help.

The fresh water tank sensor shouldn’t be subject to goop making it inaccurate. As SeaDog said, I would check the wiring on that tank’s sensors.

[2015 Flagstaff 21DS]

On my trailer the fresh water tank sits on angle steel but under extremely bad road conditions it can slide side to side. On one occasion it slid far enough to the curb side that the ground wire for the sensors was stretched and broke.

[bukhrn]

"Holding tank sensors/gauges not working right "
They seldom do.

[JimMorrell]

The factory installed sensors never work. You need to learn how and when to empty / fill your tanks.

[itat]

The factory sensors do work if you do what’s needed to keep them clean. That said, with a little experience you’ll learn how long you can go before you fill them. Then it really doesn’t matter if they’re working.

[hodag_guy]

Originally Posted by JimMorrell

The factory installed sensors never work. You need to learn how and when to empty / fill your tanks.

My black tank sensor doesn't work either. So how do I measure how full it is without the sensor? Would like to hear from the DIY types.

[Bob K4TAX]

Keeping them clean seems to go a long way in keeping them working. Multiple flushes of the tank go a long way to keeping the tank clean. Also, keeping TP out of the tank helps too. In other words "if it wasn't eaten and swallowed, it doesn't go in the tank". That means some other vessel for the TP.

As to sensors working, when you can see the level of the black tank with the flapper valve open in the toilet, the tank needs to be dumped.

If at a site with a sewer connection, it is suggested to keep the black tank dump valve closed until you are ready to dump. Maybe once every 2 or 3 days depending on usage. This keeps more liquid in the tank and helps dissolve the solids. Otherwise one will end up with a poo pyramid in the tank and that is hard to move along.

[bikendan]

Originally Posted by hodag_guy

My black tank sensor doesn't work either. So how do I measure how full it is without the sensor? Would like to hear from the DIY types.

I look down the toilet with a flashlight.

[hodag_guy]

Originally Posted by bikendan

I look down the toilet with a flashlight.

Thanks. Why didn't I think of that?

[Mandolin]

Originally Posted by GoldenBoy

re 2020 Dynamax Force. The holding tank gauges are not showing correct information. about 3 weeks ago I filled the fresh water tank and as it filled the gauge showed the progress, 1/3, 2/3, full. I just returned from a short trip and when I dumped grey tank, black tank and refilled the water tank the grey tank monitor still showed 1/3 full when empty, the black tank showed empty and the water tank gauge showed empty when full. Can someone give me some clue about what might be the problem and how to fix it?

Thanks

I had a similar problem. Someone suggested leaving the holding tank about half full, and adding a bag of ice just before leaving the campground. I tried it and the sensors now work well. The just needed to be cleaned a bit.