black tank is 2/3 full but it is empty

[RVKevin]

@Cat&Rob, howson, Country Campers, @MidwestCamper: Thanks for your suggestions. I do not believe it is a sensor wiring problem. Why? Because the very first few days the sensors worked perfectly well: after about 2 days I was 1/3 full, then 2 days I was 2/3s full, and it was at that point I dumped. (For reference: in our previous non-GD unit, we could go about 6-7 days, and its tank was 5 gal smaller, so I figured 2/3s after 4 days was reasonable. Plus, when I looked down the toilet, it looked like it might just be 2/3 full.). I’m fine with estimating “fullness” looking down the toilet, just thinking that if accurate levels on the tanks CAN be done, it should be done on the Grand Design, too. Especially given that this is the ONLY issue I have with the coach. And it’s not really that irritating.

Appreciate all the helpful comments. I do plan to bring it in for a look-at to the dealer in May, and when I do, I’ll ask them to review the wiring on the sensors.

[mpking]

I've never used it, but this guy:
https://rvwhisper.com/tank-whisper/

Claims to have improved the process.
https://uspto.report/patent/grant/10,760,937

Abstract (From my non-technical reading of the patent he got)
Normal cheap systems use resistance to measure.
More expensive systems use capacitance.
He's developed an inline board that applies capacitance principles using the resistance sensors. (Layman, the board can tell if it's water, or slime, or oil that making the electrical connection)

Not sure how this will work with the newer Control panels.

[howson]

I've never used it, but this guy:
https://rvwhisper.com/tank-whisper/

Claims to have improved the process.
https://uspto.report/patent/grant/10,760,937

Abstract (From my non-technical reading of the patent he got)
Normal cheap systems use resistance to measure.
More expensive systems use capacitance.
He's developed an inline board that applies capacitance principles using the resistance sensors. (Layman, the board can tell if it's water, or slime, or oil that making the electrical connection)

Not sure how this will work with the newer Control panels.

Wow--this looks promising if it works. I've sent them an email asking if it will work with a GX140. I don't see why not...but will post if I get a response.

[gkockrow]

Any one have trouble with straps that hold tanks in place breaking? Never towed when full and now I have on sitting on axel. 273 MK 2019. Thanks.

[TucsonJim]

Any one have trouble with straps that hold tanks in place breaking? Never towed when full and now I have on sitting on axel. 273 MK 2019. Thanks.

Welcome to the forum.

Can you be a little more specific? I'm not familiar with a "273 MK", and I don't appear to have a drawing set for it. What product line is that in? Transcend, Imagine, etc?

Jim

[Lonestar]

TucsonJim

Reflection 150 Series.

[TucsonJim]

Thanks Lonestar - I don't have any info at all on that one. No drawings, and it's not on the GDRV website any more. I was going to look at the holding tank drawings, but unfortunately, I don't have them.

Jim

[Lonestar]

Thanks Lonestar - I don't have any info at all on that one. No drawings, and it's not on the GDRV website any more. I was going to look at the holding tank drawings, but unfortunately, I don't have them.

Jim

I just PM'ed the drawings to you.

Jerry

[TucsonJim]

I just PM'ed the drawings to you.

Jerry

Awesome Jerry. Thanks!

gkockrow - After looking at the drawing that Jerry sent me, the only tank over the axle is the fresh water tank. There have been instances of fresh tanks falling in the past. On a 2019, there should have been some metal straps to keep this from happening. It is possible that the straps have failed. In the photo below, you can see how the tank in my 2017 Reflection 297RSTS is held with metal straps.