Compass Connect not displaying tank level above empty

[shnngns]

Hello all! I have a 2021 2800bh that came with the Compass Connect controller and X180T board. This unit is set up to display tank levels both on the physical display and on the app. My first trip out I ended up with overflowing Gray tank 1 and Gray tank 2. The display and app still showed empty. I have reached out to GD and they sent me the schematics of the x180t so I checked all of the tank sensor connections and made sure they were tight. For about a half a second I got readings on two of the tanks and then they all went back to empty. My question is where do the wires from the X180T go? Do they connect to another "brain" for tank levels? I've never researched how the tank sensors work and am looking for some guidance. My local dealer is almost 3 hours away and we are in the middle of camping season so I'd much rather try and solve myself. I thought about getting a mobile repair which GD did authorize, but I'm concerned about them working on a new controller on a new camper that they may have zero experience with. Thanks!

[howson]

shnngns

Great questions (and welcome to the forum).

First off, remember we can't post any GD diagram here on the forum (gentle reminder) so we'll have to do our best to describe what we're looking at to figure out the problem.

I see five inputs on the Configurable Switch Inputs side of the X180T (on the 2800BH). Does that match what you have?

The X180T most likely communicates with the unique Imagine Monitor Panel through the CANBUS (a digital interface).

The picture below is from a Lippert training video. What I'm trying to show you is the inputs to the X180T are the output of a tank harness connector. In the mock up below it's the pink wire. Note the probes go to a harness junction (black thing) then that output goes to the tank monitor input. Again, that's the pink wire in the picture.



Each tank harness is going to have it's own power wire and ground wire. Where the tank wires come together to get power and ground...I don't know. I assume at the X180T. There could be a group of wires crimped together and connected to the X180T that have a bad connection. You might try wiggling the wires that come off the power and ground lugs (be careful with power on!).

One other "from left field" thought. Check the back of the Control Panel and ensure it is the right panel for your 2800BH. It will have a sticker on it designating which floor plan(s) it works with.

For the casual reader...remember that the Imagine has a unique implementation of the CompassConnect system. None of the other lines are configured like the Imagines.

Howard

P.S. If I haven't sent you screaming off to a far corner......please check out the Welcome Letter to New Members at https://gdrvowners.com/forum/main-fo...to-new-members

[Giesis]

Hello all! I have a 2021 2800bh that came with the Compass Connect controller and X180T board. This unit is set up to display tank levels both on the physical display and on the app. My first trip out I ended up with overflowing Gray tank 1 and Gray tank 2. The display and app still showed empty. I have reached out to GD and they sent me the schematics of the x180t so I checked all of the tank sensor connections and made sure they were tight. For about a half a second I got readings on two of the tanks and then they all went back to empty. My question is where do the wires from the X180T go? Do they connect to another "brain" for tank levels? I've never researched how the tank sensors work and am looking for some guidance. My local dealer is almost 3 hours away and we are in the middle of camping season so I'd much rather try and solve myself. I thought about getting a mobile repair which GD did authorize, but I'm concerned about them working on a new controller on a new camper that they may have zero experience with. Thanks!

I have the same year model you have with the same X180T. You are not going to like what I am going to tell you but my levels for the Black and Grey tanks only worked once. Every now and then it goes from empty to full just because. On my first trip I figure out it takes three days for the bathroom tank to fill up and the kitchen about 7 days. We are a family of 5. you can have the dealer fixe it if you want to, but they will not work right after a few uses.

I ordered the SeeLevel II tank monitor and installed it on the black tank first just to try it and it works great. I am waiting until camping season is over to install it on the gray tanks.

[howson]

Giesis

For clarification, are you stating the sensors are inaccurate (common) or don't indicate anything (not common)?

[Giesis]

Giesis

For clarification, are you stating the sensors are inaccurate (common) or don't indicate anything (not common)?

The sensors just suck. Very inaccurate. They indicate. Empty all the time.

[howson]

The sensors just suck. Very inaccurate. They indicate. Empty all the time.

If the sensors are getting power, they will indicate a voltage on the output of the sensor harness (the wire going into X180T). Me myself and I would be checking each of those inputs for a voltage level when the tanks are empty and then with water in at least the grays. If there's a voltage difference the problem is the programming sent from the control panel to the X180T. If there's no voltage on any of those wires there's a power problem.

The sensors are inaccurate but mine have never shown empty all the time.

There is the factor that even if we figure this out...they are not reliable indicators anyway, so whether or not it's worth the time to try and figure this out is up to the owner.

Howard

[Captain Peachfuzz]

I'm new to this, so if I step on somebody's toes, please let me know.

Did anyone notice that the photograph shown in the Lippert training video can't possibly work?
There are three probes in the tank that go through three wires to a black blob. That black blob likely contains a couple of resistors that scale current flows depending on which probe is contacting liquid. Only one wire exits the blob and goes to the controller, but it takes two wires to measure anything.

For this system to work there must be a second wire that also connects to the liquid in the tank. The liquid needs to be deliberately connected to a voltage source or to chassis.

If there is no intentional connection from the liquid in the tank to chassis or to a voltage source, the system might work sporadically if the liquid can find an unintentional electrical path to chassis.....

[howson]

I'm new to this, so if I step on somebody's toes, please let me know.

Did anyone notice that the photograph shown in the Lippert training video can't possibly work?
There are three probes in the tank that go through three wires to a black blob. That black blob likely contains a couple of resistors that scale current flows depending on which probe is contacting liquid. Only one wire exits the blob and goes to the controller, but it takes two wires to measure anything.

For this system to work there must be a second wire that also connects to the liquid in the tank. The liquid needs to be deliberately connected to a voltage source or to chassis.

If there is no intentional connection from the liquid in the tank to chassis or to a voltage source, the system might work sporadically if the liquid can find an unintentional electrical path to chassis.....

No worries--I wear steel toed boots.

I don't claim total expertise on tank systems or Lippert's setups, but I suspect the voltage levels are compared to ground (white wire) in the controller.

Welcome to the forum, BTW! I hope you'll take a moment and read the Welcome Letter to New Members at https://gdrvowners.com/forum/main-fo...to-new-members

Howard

[Jlawles2]

I would suspect that it's really a 4 wire system and they did not connect the ground wire as its just a common ground for the whole system and does not run through the box. That black box probably has resistors in it which change the voltage to each wire and the wire back to the controller just carries the voltages.

[Captain Peachfuzz]

Yup. For the system to work, there has to be a return wire connected to the liquid in the tank. Three level sensing probes and a return makes four wires to the tank, so I agree. I also agree that the return could be through the chassis. The problem I have is that the liquid in the tank has to somewhere be connected to the return, and that connection needs to be at the lowest point of the tank so the probes work at all liquid levels. That connection isn’t obvious to me. The tank is plastic, the pipes are plastic, mounting bolts don’t usually penetrate the tank, gate valves are plastic. So where does the liquid in the tank get connected to chassis or to a return wire? There needs to be something metal at a low point inside the tank that is connected to the return or chassis. Where is it?

[howson]

Yup. For the system to work, there has to be a return wire connected to the liquid in the tank. Three level sensing probes and a return makes four wires to the tank, so I agree. I also agree that the return could be through the chassis. The problem I have is that the liquid in the tank has to somewhere be connected to the return, and that connection needs to be at the lowest point of the tank so the probes work at all liquid levels. That connection isn’t obvious to me. The tank is plastic, the pipes are plastic, mounting bolts don’t usually penetrate the tank, gate valves are plastic. So where does the liquid in the tank get connected to chassis or to a return wire? There needs to be something metal at a low point inside the tank that is connected to the return or chassis. Where is it?

I'll have to leave your question to someone more knowledgeable about how the system actually works. All I know is liquid touches the sensor and, through a corresponding voltage level passed to a sequence of lights (or controller), a reading is obtained.

The reason the sensors are so unreliable is because instead of liquid it can be "stuff" stuck to a sensor (that physically is inserted into the tank) triggering a reading even when the tank is empty. Thus the many concoctions and strategies to keep the sensors clean. Complete nuisance.

I am confident it is our lack of knowledge on how the system works that is the issue--pretty sure the trainers at Lippert know what they are doing.

[Captain Peachfuzz]

I hear you, but as an electronic design engineer with roughly forty years of product design experience, I don’t share your faith. As I have dug into how the tank level monitor systems work, I’ve been disappointed by what I’ve found. In my opinion, the three probe scheme with a ‘harness’ that reduces three probes to one wire (plus common) returned to the monitor is a lousy design that will be prone to false level indications. I believe that the industry moved to the current scheme purely to reduce cost, and in the process left behind a better performing scheme (one in which a wire from each probe, three or four per tank, is routed separately to comparators in the monitor).

[howson]

Captain Peachfuzz -- no argument from me. I don't even use the systems. Too unreliable. A recent thread by bellis where he's investigating using the new Victron GX Tank 140 (with new probes) is very intriguing to me since I have a Victron Color Control GX.

If you're interested, please check out this thread: https://gdrvowners.com/forum/operati...ank-monitoring I'd be very interested in reading your .02 as I'm still learning about this segment of Victron's lineup.

Howard

[Jlawles2]

Captain Peachfuzz Capt, The picture is not correct in that it is missing the ground. Usually the 4 sensor wires are somewhat in a line, or the ground and 1/3rd wire are at about the same level. Ground wire is the closest to empty or lowest so it sees liquid first.

This is probably what you were looking to see:

https://rvlifemag.com/on-the-level-g...are-important/ in this link you see the old school sensors on right and some upgrade on the left.

https://www.rv.net/forum/index.cfm/f...print/true.cfm

[shnngns]

Giesis

For clarification, are you stating the sensors are inaccurate (common) or don't indicate anything (not common)?

Only the empty leds light up. Never shows anything above empty.