Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×
 

Go Back   Thor Forums > Thor Tech Forums > Maintenance and Repair
Click Here to Login
Reply
 
Thread Tools Display Modes
 
Old 07-04-2022, 09:54 PM   #1
Junior Member
 
Brand: Thor Motor Coach
State: Kansas
Posts: 11
THOR #26844
Question On Holding Tank Indicator Lights

Good Day,

I bought a used 2005 very well taken care of Four Winds Chateau motorhome. It appears that the holding tank 1 and holding tank 2 indicator lights are showing low level permanently. My gray water tank was completely full and was showing low level yet. Where do I head in at on fixing this? The tanks and sensors are fairly easy to get to.

Thanks fellows!

__________________
monteu is offline   Reply With Quote
Old 07-04-2022, 10:04 PM   #2
Senior Member
 
The Gritz Carlton's Avatar
 
Brand: Thor Motor Coach
Model: THOR Chateua 35SF
State: Florida
Posts: 4,664
THOR #11130
You'll never get them to work right. Over time you'll get to know pretty closely what's in them.
__________________
2018 THOR Chateau 35SF
Two Labs, Bugsie & Blondie
The Gritz Carlton is offline   Reply With Quote
Old 07-04-2022, 10:12 PM   #3
Senior Member
 
Brand: Thor Motor Coach
Model: Fourwinds 24F
State: North Carolina
Posts: 545
THOR #9511
I found this one day surfing…might be helpful, might not be.
__________________
JimOIB is offline   Reply With Quote
Old 07-04-2022, 10:52 PM   #4
Senior Member
 
Pillbox's Avatar
 
Brand: Thor Motor Coach
Model: Four Winds
State: California
Posts: 309
THOR #24260
Add dawn soap to the tanks after draining them.
Terry
__________________
Terry and Geri
2017 Four Winds 35SD
2020 Grand Cherokee Toad
Semper Fi
Pillbox is offline   Reply With Quote
Old 07-04-2022, 11:19 PM   #5
Senior Member
 
Brand: Thor Motor Coach
Model: 2013 ACE 30.1
State: Alberta
Posts: 1,382
THOR #2631
Typically black and grey tanks can have their high mounted level sensors contaminated and will indicate a tank is full on the monitor panel, when in fact it may actually be less full or even be empty. In this case the OP is saying the tank is actually full and still reads empty. I would try checking if the ground sensor for the tanks is connected at the tank monitor point OK and also if the tank monitor points resistor pack sensing unit is connected through to the monitor panel OK. The resistor pack may have failed open also? Depending on how your tank sensor system is set up a high resistance (like open tank ground; or an open or disconnected tank resistor sensing unit wire) could indicate empty tanks to the monitor panel, when they are actually full. Not sure how your tanks are connected but a simple system diagram is attached. Of course this may not apply to your coach.
Attached Thumbnails
Click image for larger version

Name:	Basic Schematic of level sensing.jpg
Views:	42
Size:	30.5 KB
ID:	38518  
__________________
javelin is offline   Reply With Quote
Old 07-05-2022, 12:11 AM   #6
Site Team
 
16ACE27's Avatar
 
Brand: Thor Motor Coach
Model: ACE 27.1
State: Florida
Posts: 9,755
THOR #7035
Javelin is correct - when the sensors get dirty they indicate a higher than actual tank level. You have the opposite problem. Probably a loss of power to the sensors. I'd start behind the panel with the LEDs and check wire connections.
__________________
Ted & Melinda
2016 ACE 27.1
2016 Chevy Sonic Toad
2020 Chevy Colorado Z71 Trail Runner Alternate Toad
16ACE27 is offline   Reply With Quote
Old 07-05-2022, 12:50 AM   #7
Senior Member
 
Brand: Thor Motor Coach
Model: Chateau 24F
State: Ohio
Posts: 2,254
THOR #16721
It's a big ask to expect the typical tank sensor system to function perfectly after 17 years. They use flimsy low-gauge wiring, because it works using a low voltage resistance principle.

Do some research on how the system works... it's really pretty basic. Check the connections on the back of the wall panel. Crawl under and check the wire connectors on the side of each tank. If you get good continuity from panel to sensors - no broken wires - focus on cleaning the inside of the tanks.

I suggest completely filling your waste tanks with soapy water and soaking them for several days... Driving around to agitate the water helps. Then flushing completely. It might take several cycles of this for results. You never really know how well those tanks were maintained and flushed.

Good luck!
__________________
A positive attitude makes you focus on solutions and success, rather than on setbacks or stress.
-Samy Azer, Navigating Problem-based Learning
Chateau_Nomad is offline   Reply With Quote
Old 07-05-2022, 11:31 AM   #8
Junior Member
 
Brand: Thor Motor Coach
State: Kansas
Posts: 11
THOR #26844
Thanks everyone, I'll try what was suggested here. I crawled under and both tanks have a wire disconnected. I'll start with that.
__________________
monteu is offline   Reply With Quote
Old 07-05-2022, 12:05 PM   #9
Senior Member
 
Bob Nodine's Avatar
 
Brand: Thor Motor Coach
Model: Quantum JM31
State: Tennessee
Posts: 313
THOR #21926
Quote:
Originally Posted by monteu View Post
Good Day,

I bought a used 2005 very well taken care of Four Winds Chateau motorhome. It appears that the holding tank 1 and holding tank 2 indicator lights are showing low level permanently. My gray water tank was completely full and was showing low level yet. Where do I head in at on fixing this? The tanks and sensors are fairly easy to get to.

Thanks fellows!
One of the first mods I make to any RV we acquire is to install SeeLevel Tank sensors. They are on the outside of the tanks and are not affected by toilet paper, etc. inside the tanks. The new SeeLevel has Bluetooth and we can check our tank levels using an app on the phone. Love that. That makes it unnecessary to install the tank monitor inside the RV. On our Quantum JM31 we left the OEM tank level system intact but do not use it.

https://tinyurl.com/2lj4ddae

We were able to mount the SeeLevel display in the service bay near where the tanks and tank sensors are accept the fresh water tank under the bed. Was not difficult to run a pair of wires to the tank under the bed.
Attached Thumbnails
Click image for larger version

Name:	SeeLevel Display.jpg
Views:	16
Size:	65.2 KB
ID:	38533   Click image for larger version

Name:	Screenshot_20210705-072548_Garnet RV.jpg
Views:	11
Size:	45.5 KB
ID:	38534  

Click image for larger version

Name:	Fresh water tank level sensor.jpg
Views:	20
Size:	95.7 KB
ID:	38535  
__________________
Bob
2022 Quantum JM31, 2020 Chevy Sonic
Bob Nodine is offline   Reply With Quote
Old 07-05-2022, 05:13 PM   #10
Site Team
 
16ACE27's Avatar
 
Brand: Thor Motor Coach
Model: ACE 27.1
State: Florida
Posts: 9,755
THOR #7035
Quote:
Originally Posted by monteu View Post
Thanks everyone, I'll try what was suggested here. I crawled under and both tanks have a wire disconnected. I'll start with that.
Makes you go "Hmmmmmmm"
__________________
Ted & Melinda
2016 ACE 27.1
2016 Chevy Sonic Toad
2020 Chevy Colorado Z71 Trail Runner Alternate Toad
16ACE27 is offline   Reply With Quote
Old 07-05-2022, 05:43 PM   #11
Senior Member
 
Pillbox's Avatar
 
Brand: Thor Motor Coach
Model: Four Winds
State: California
Posts: 309
THOR #24260
Hmmmmmmm
__________________
Terry and Geri
2017 Four Winds 35SD
2020 Grand Cherokee Toad
Semper Fi
Pillbox is offline   Reply With Quote
Old 07-05-2022, 11:22 PM   #12
Senior Member
 
Brand: Thor Motor Coach
Model: Chateau 24F
State: Ohio
Posts: 2,254
THOR #16721
At the beginning of season two with our 2020 class C, I noticed a string of wires hanging down in the rear under the coach. On inspection, the sensor wires from the black tank looked like they were installed by my 3 year old grandson. They were half-assed taped to the side of the tank... which of course came loose. No wire loom for protection, no silicone over the bare screw connectors...nothing.

Seriously - these wires could be twisted together into a loom and zip tied more permanently. Less than $20 in labor & materials and future peace of mind. Just horrible execution, and a guaranteed failure point.
__________________
A positive attitude makes you focus on solutions and success, rather than on setbacks or stress.
-Samy Azer, Navigating Problem-based Learning
Chateau_Nomad is offline   Reply With Quote
Old 07-06-2022, 02:11 AM   #13
Junior Member
 
Brand: Thor Motor Coach
State: Kansas
Posts: 11
THOR #26844
How important are the grounds in a system like this? I fixed the two wires that were pulled apart, one on each tank. It's still not working, however there is a ground bolt there that looks really rusty and I think these sensors run to it looks like. I already fixed the electric step and generator starter by cleaning the ground a few weeks ago.
__________________
monteu is offline   Reply With Quote
Old 07-06-2022, 02:48 AM   #14
Senior Member
 
Brand: Thor Motor Coach
Model: 2013 ACE 30.1
State: Alberta
Posts: 1,382
THOR #2631
The ground connection to the low mounted reference sensor terminal on each tank is critical to the correct operation of the monitor panel. As fluid levels rise in each tank they provide a conductive path between the ground sensor terminal and the next level up sensor(s). Since we don’t know your specific system we can only speculate that perhaps the two loose wires you found are the ground sensor terminal wires from each tank that both connect to a common chassis ground point. Do the two loose wires trace back to the lowest terminals on each tank (with three additional sensor terminals mounted above them on each tank)? Does the rusty ground terminal you refer to, have a crimp connector still under a nut that may have been where the two loose tank wires were pulled from? Some wiring diagrams show a white wire as the common ground wire.....but we are really just guessing on how your coach is wired.
__________________
javelin is offline   Reply With Quote
Old 07-06-2022, 03:56 AM   #15
Senior Member
 
Brand: Thor Motor Coach
Model: Chateau 24F
State: Ohio
Posts: 2,254
THOR #16721
Quote:
Originally Posted by monteu View Post
How important are the grounds in a system like this? I fixed the two wires that were pulled apart, one on each tank. It's still not working, however there is a ground bolt there that looks really rusty and I think these sensors run to it looks like. I already fixed the electric step and generator starter by cleaning the ground a few weeks ago.
You'll have to trace the wires. As the fluid in the tank reaches a sensor, it essentially causes an electrical circuit to complete which illuminates the light on the panel. You'll need to check continuity of all the wires and find where they terminate. It's basically a DC circuit with a positive voltage wire and a ground wire, with the tank "sensor" acting like a switch.
__________________
Chateau_Nomad is offline   Reply With Quote
Old 07-06-2022, 11:05 AM   #16
Senior Member
 
Brand: Thor Motor Coach
Model: Fourwinds 24F
State: North Carolina
Posts: 545
THOR #9511
Quote:
Originally Posted by monteu View Post
How important are the grounds in a system like this? I fixed the two wires that were pulled apart, one on each tank. It's still not working, however there is a ground bolt there that looks really rusty and I think these sensors run to it looks like. I already fixed the electric step and generator starter by cleaning the ground a few weeks ago.

The PDF In post #3 shows the wiring and how to test everything. While it is for an older panel the basic design has not changed in years.
__________________
JimOIB is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Featured Campgrounds

Reviews provided by

Disclaimer:

This website is not affiliated with or endorsed by Thor Industries or any of its affiliates. This is an independent, unofficial site.




All times are GMT. The time now is 10:14 AM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2022, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0 PL2