Replacing tank sensors - does anybody know where they are?

[Engineersaab54]

The "Amber Alert" on our 2017 Dutch Star 4369 pretty much stays on all the time, until it turns red (more on that in a minute). After serious, repeated rinsing of the black tank I can sometimes persuade it to stay off for two or three flushes or a few more. But it's always glowing warmly again within half a dozen flushes. After much searching, I learned that the tank sensors are located on the Outside of the tanks, not internally - so all the sage advice all over the web about cleaning internal sensors is pretty much useless. Short form (so you don't have to read the rest of this novella unless you just want to): I purchased replacement sensors from the parts department at Newmar, and have explored deep inside the tank bay (behind the pegboard in Bay #3 on the passenger side), but I cannot locate even a wiring harness resembling the one from the new sensors, much less the sensors themselves!

It doesn't seem reasonable that some build-up on the sides of the tank interior to the sensors' exterior position could be removed sufficiently by diligent rinsing, only to rebuild itself within a few flushes. On the other hand, if it's simply defective sensors, why would they respond at all to extensive rinsing? Coincidence? I have used Borax and Dawn and sloshed a mostly empty tank down miles of always-under-construction-US highways. Sometimes that results in the amber light going out temporarily - oftentimes not. I always do a very thorough dump and rinse before we move locations, and generally travel with the black and grey tanks empty. Sometimes, when we arrive at our destination later in the day, the amber light, which had not gone out after rinsing, has gone out during travel. But more often, after being off when we pulled out earlier in the day, the amber light is back on by the time we arrive at our destination, even though the tank has remained empty all day. Go figure.

I don't mind the amber glow, really; it's a nice color for one thing, and easy to ignore once you learn that it's generally lying to you! When it finally turns red, if we're hooked up to shore water (if external power is "shore power", then external water must be "shore water", even if it comes from a well, right? I digress.) we can just pull the 10A fuse in the DC panel in the half-bath. That fuse controls both the water pump (not needed when connected to shore water) AND the sensor circuit, which includes the DigiLevel display up in the control panel and the lights at the toilets. When the lights are red, indicating a full tank, the circuit will not allow you to pump water and/or flush the toilets. Makes sense. IF the red light wasn't just as big a liar as the amber light! We have rarely, if ever, filled the black tank. But the red light has come on several times when we knew the tank wasn't even close to being full.

The pain in the bohunkus comes when boondocking. When we get a false full signal which makes us see red (lights), the only way to continue using the toilets is to pull the fuse, disabling the sensor circuit, and enabling us to flush. The fuse must be replaced to pump water from the onboard tanks for other uses. Hence the desire to fix this and install new sensors, to see if that will stop the lights from lying. But I can't replace them if I can't find them.

 

[Engineersaab54]

The "Amber Alert" on our 2017 Dutch Star 4369 pretty much stays on all the time, until it turns red (more on that in a minute). After serious, repeated rinsing of the black tank I can sometimes persuade it to stay off for two or three flushes or a few more. But it's always glowing warmly again within half a dozen flushes. After much searching, I learned that the tank sensors are located on the Outside of the tanks, not internally - so all the sage advice all over the web about cleaning internal sensors is pretty much useless. Short form (so you don't have to read the rest of this novella unless you just want to): I purchased replacement sensors from the parts department at Newmar, and have explored deep inside the tank bay (behind the pegboard in Bay #3 on the passenger side), but I cannot locate even a wiring harness resembling the one from the new sensors, much less the sensors themselves!

It doesn't seem reasonable that some build-up on the sides of the tank interior to the sensors' exterior position could be removed sufficiently by diligent rinsing, only to rebuild itself within a few flushes. On the other hand, if it's simply defective sensors, why would they respond at all to extensive rinsing? Coincidence? I have used Borax and Dawn and sloshed a mostly empty tank down miles of always-under-construction-US highways. Sometimes that results in the amber light going out temporarily - oftentimes not. I always do a very thorough dump and rinse before we move locations, and generally travel with the black and grey tanks empty. Sometimes, when we arrive at our destination later in the day, the amber light, which had not gone out after rinsing, has gone out during travel. But more often, after being off when we pulled out earlier in the day, the amber light is back on by the time we arrive at our destination, even though the tank has remained empty all day. Go figure.

I don't mind the amber glow, really; it's a nice color for one thing, and easy to ignore once you learn that it's generally lying to you! When it finally turns red, if we're hooked up to shore water (if external power is "shore power", then external water must be "shore water", even if it comes from a well, right? I digress.) we can just pull the 10A fuse in the DC panel in the half-bath. That fuse controls both the water pump (not needed when connected to shore water) AND the sensor circuit, which includes the DigiLevel display up in the control panel and the lights at the toilets. When the lights are red, indicating a full tank, the circuit will not allow you to pump water and/or flush the toilets. Makes sense. IF the red light wasn't just as big a liar as the amber light! We have rarely, if ever, filled the black tank. But the red light has come on several times when we knew the tank wasn't even close to being full.

The pain in the bohunkus comes when boondocking. When we get a false full signal which makes us see red (lights), the only way to continue using the toilets is to pull the fuse, disabling the sensor circuit, and enabling us to flush. The fuse must be replaced to pump water from the onboard tanks for other uses. Hence the desire to fix this and install new sensors, to see if that will stop the lights from lying. But I can't replace them if I can't find them.

Well, after all this brilliant editorial work, I searched the forum and found the answer. Duh. As I feared, the sensors are hiding behind the wet panel, according to sources, who also say that the wet panel is THAT hard to remove. It's reinstalling it that concerns me....

 

[Engineersaab54]

Well, after all this brilliant editorial work, I searched the forum and found the answer. Duh. As I feared, the sensors are hiding behind the wet panel, according to sources, who also say that the wet panel is THAT hard to remove. It's reinstalling it that concerns me....

Is NOT that hard to remove...

 

[Canaddar]

The "Amber Alert" on our 2017 Dutch Star 4369 pretty much stays on all the time, until it turns red (more on that in a minute). After serious, repeated rinsing of the black tank I can sometimes persuade it to stay off for two or three flushes or a few more. But it's always glowing warmly again within half a dozen flushes. After much searching, I learned that the tank sensors are located on the Outside of the tanks, not internally - so all the sage advice all over the web about cleaning internal sensors is pretty much useless. Short form (so you don't have to read the rest of this novella unless you just want to): I purchased replacement sensors from the parts department at Newmar, and have explored deep inside the tank bay (behind the pegboard in Bay #3 on the passenger side), but I cannot locate even a wiring harness resembling the one from the new sensors, much less the sensors themselves!

It doesn't seem reasonable that some build-up on the sides of the tank interior to the sensors' exterior position could be removed sufficiently by diligent rinsing, only to rebuild itself within a few flushes. On the other hand, if it's simply defective sensors, why would they respond at all to extensive rinsing? Coincidence? I have used Borax and Dawn and sloshed a mostly empty tank down miles of always-under-construction-US highways. Sometimes that results in the amber light going out temporarily - oftentimes not. I always do a very thorough dump and rinse before we move locations, and generally travel with the black and grey tanks empty. Sometimes, when we arrive at our destination later in the day, the amber light, which had not gone out after rinsing, has gone out during travel. But more often, after being off when we pulled out earlier in the day, the amber light is back on by the time we arrive at our destination, even though the tank has remained empty all day. Go figure.

I don't mind the amber glow, really; it's a nice color for one thing, and easy to ignore once you learn that it's generally lying to you! When it finally turns red, if we're hooked up to shore water (if external power is "shore power", then external water must be "shore water", even if it comes from a well, right? I digress.) we can just pull the 10A fuse in the DC panel in the half-bath. That fuse controls both the water pump (not needed when connected to shore water) AND the sensor circuit, which includes the DigiLevel display up in the control panel and the lights at the toilets. When the lights are red, indicating a full tank, the circuit will not allow you to pump water and/or flush the toilets. Makes sense. IF the red light wasn't just as big a liar as the amber light! We have rarely, if ever, filled the black tank. But the red light has come on several times when we knew the tank wasn't even close to being full.

The pain in the bohunkus comes when boondocking. When we get a false full signal which makes us see red (lights), the only way to continue using the toilets is to pull the fuse, disabling the sensor circuit, and enabling us to flush. The fuse must be replaced to pump water from the onboard tanks for other uses. Hence the desire to fix this and install new sensors, to see if that will stop the lights from lying. But I can't replace them if I can't find them.

We have a 2017 DS 4369 as well. I might be able to save you a bunch of pain.

For starters, we have had the same issue as you. Everything worked well when we got the coach. Not many months after, the 60% light came on and just never went out. It has been this way for around 6 years and I was just resigned to that being the way it is........but then I saw a video on YouTube.....

They were pressure washing an RV's black tank out and got all kinds of crazy crap (literally and figuratively.lol) out of it. Here is the short version. You need a power washer, a pressure hose and a nozzle that goes on that hose. You will feed the hose up thru your drain port while it is turned on and it sprays high pressure water in jets at different angles and cleans everything.

I did this and my lights have all been working great for the last month. This was a lot easier than replacing sensors. It was also a lot cheaper than taking it to a repair shop. Yes, I gave my RV an enema.

I already had a power washer (110v, about 2,000 psi) so I had no additional cost there. I bought the hose and fittings that I needed from Amazon for about $37, and I bought a Y fitting for the sewage hose from Walmart for about $10.

I connected the Y fitting to my sewage line and then connnected the hose running to the sewage drain. This left me with an open port that I rotated to face up. I then inserted my pressure hose thru that port to force it up into the black tank. Surprisingly (and thankfully), I was not getting spillage thru that open port.

Overall, I spent about $50 and 1 to 2 hours of time doing this. It was a pretty easy job. Doing anything with sewage is gross, but it was a lot less messy than I had expected it to be. I tried to get the pressure hose up into my grey tank as well, but was not able to get it there because of sharper bends and a smaller pipe diameter.

Here is a link for the YouTube video that set me on the path: There are several other similar videos by others on youtube as well.

Here is the kit that I ordered on Amazon: www.amazon.com/dp/B0C4FR758T?ref=ppx_yo2ov_dt_b_product_details&th=1

As for your original question, I believe that the level sensors are inside the tank on your RV. Behind the right side pegboard, you see the black tank. On top of it, close to the right side is a plug inserted into the tank. I think that is your level sensor (but not positive as I never pulled it out).