# Water tank sensor



## wp1234

Just wondering if anyone’s ever had a problem with the fresh water tank sensor in their Autotrail tank. For some reason mine is showing 100% full all the time even when the tanks empty ? 
Any thoughts on a solution gratefully accepted


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## Sargent

Hi wp1234, has this just happened? ie was ok and isn't? if this is the case then check the 6 way connector that connects the sensor to the vehicle harness, if this has got wet then it will be measuring the connector instead of the sensor, if this is the case, then dry both halves of the connector and place out of water contamination.

If you want to check that you are on the right path, if you check level reading with the connector parted (but make sure the connector is dry)

The signals ie the various levels add up (if this makes sense) so you can simply connect each colour to the white, one by one increasing the reading by 25%

I hope this helps, but if you need further info please let me know?

Best regards

Ian Sargent


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## lindyloot

Hi we have a problem with ours. Can you tell us where the sensors and connectors are located. It is an intermittent problem with waste and fresh water reading they appear to be inacuurate/fluctuating. IMO they are poorly designed . Many thanks
Rich.


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## wp1234

Sargent said:


> Hi wp1234, has this just happened? ie was ok and isn't? if this is the case then check the 6 way connector that connects the sensor to the vehicle harness, if this has got wet then it will be measuring the connector instead of the sensor, if this is the case, then dry both halves of the connector and place out of water contamination.
> If you want to check that you are on the right path, if you check level reading with the connector parted (but make sure the connector is dry)
> The signals ie the various levels add up (if this makes sense) so you can simply connect each colour to the white, one by one increasing the reading by 25%
> I hope this helps, but if you need further info please let me know?
> 
> Best regards
> 
> Ian Sargent


Hi Ian , Thanks for the very quick reply .Yes it was fine last week but today on refilling the tank it has stuck on 100% even though tank was not full.
Can you tell me where the 6 way connector to vehicle harness 
is located and I will check in the morning
Thanks in advance
Wyn


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## MicknPat

WP1234,

This appears to be a common problem with tanks fitted to motor homes.

On our RV the 50 gallon fresh water tank LED display shows: 

1/4 = Empty
1/2 =1/4
3/4 = 1/2
Full = 3/4

But at least I know and can act accordingly. :wink: 

Mick


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## Sargent

Hi Wyn, the connector is located under the vehicle in line with the Toilet breakout, it should be located away from water thrown up underneath the vehicle. i hope this helps

One other point to check is that if the water has flowed over the sensors in the side of the tank this can again cause false readings.

If you send me a PM i will give you a call in the morning? if that helps

Best regards

Ian S


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## CliveMott

Two things associated with this sensing system if its similar to that fitted to our previous Autotrail Scout. 
The system relies on a row of metal screws through the tank at varying depths. A small voltage is applied to each of the screw heads by the electronics and when the water is above each screw head a small current flows. Its a sensitive system which works well when new. 

1 Any dampness or corrosion in any of the in-line connectors can result in erroneous water level indications. 
2 From time to time you need to remove and clean out the tank removing the access cover so that any algae over the screw heads can be cleaned away. The damp retained by algae or any other gunge can make the sensor system think the tank is full even if its empty. 

Hope that helps. 

C.


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## Zebedee

Hi WP

Reckon I have the cure. :wink: 

Let our vans nuzzle up to each other for a while . . . my gauge shows 0% however much or little water is in there!! :roll: 

Thanks to Ian for the advice. I'll be under the van when the damn snow has gone to have a wriggle at the connector, if I can find it.

Dave


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## moblee

Hello wp

(You may not have the same set up as me) but I use to have the same problem on my Kontiki (Ian s) told me on top of my Fresh water tank theres a sender unit take the lid off & theres a pcboard held with 5 tiny nuts which were all loose, Finger tightened them & never had a problem since.
As i've said yours may not be the same..Just trying to give you a extra option.


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## teal

I had the waste tank light on all the time and having got underneath and saw a wire had disconnected to the tank sensor. problem solved.


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## lookback

> Hi Ian , Thanks for the very quick reply .Yes it was fine last week but today on refilling the tank it has stuck on 100% even though tank was not full.
> Can you tell me where the 6 way connector to vehicle harness
> is located and I will check in the morning
> Thanks in advance
> Wyn


Hi Wyn, Any sucess with your fresh water tank indicator. I have the same problem as you - stuck on 100%

Ian


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## DTPCHEMICALS

Our cheyenne has always a faulty reading on waste tank.
It reads 100% full some days and empty on others.

It can only be full or very nearly so when my fresh tank is empty.

dave p


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## ianhc

Hi all, my Chieftain has exactly the same problem and has had this problem for 18 months. Just unreliable, sometimes works ( i think) and other times even when empty reads 100% full. Seems like another Autotrail trait??


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## Sargent

Hi all if the waste tank is stuck at 100% this is most likely to be the float switch in the tank which to be polite has stuck with contaminants, to prove this (if) you can locate the Purple/Red wire running to the waste tank and disconnect it, this should clear the 100% indication.

If the problem is with the fresh water then the starting point i would suggest is to look at the connector to the fresh water tank which is located within 500mm of the water tank, this is likely to be concealed, again if this connector can be disconnected the fault can be traced to the connector, tank or wiring. please send me a PM and i will ask someone to get in touch or give our technical people a call 01482 678981

I hope the points above are helpful but if we can assist please let me know.

Best regards

Ian Sargent


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## tviall

I'm watching this thread with great interest. I have an AT Chieftain which flashes between 75% and 100% full. Following Ian's advice I'll check the connectors but would be interested to know from others if this has worked for them.

Tony


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## lookback

As soon as we get the dryer weather - hopefully from Tuesday next week I will dive under the motorhome and check the freshwater tank electrical connectors.

Ian


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## lookback

lookback said:


> As soon as we get the dryer weather - hopefully from Tuesday next week I will dive under the motorhome and check the freshwater tank electrical connectors.
> 
> Ian


Well I dived under my Autotrail Cheyenne this morning and located the white socket connector described in Ian Sargent`s memo. With help from Dan at Ian Sargent`s workshop and after some investigative tests, it was found that the connector - although appeared dry - had some oxidisation on the metal contacts. I played a hairdryer on the disconnected socket then sprayed with WD 40 and, voila - all is back to normal showing a 0% empty tank as it should.

Thankyou Ian and Dan

Ian


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## CliveMott

Methinks that such connectors in environments like this should be totally waterproof. Perhaps the AMP/TYCO JPT range, one variant know as SAAB connectors should be used?

Have a look at this range, here,s a sample of a 6 pole variant sealed wire by wire.
http://search.tycoelectronics.com/e...nics&search_type=Part&question_box=1-967241-1

Poles span between 2 and 70 ways. In-line and harness to PCB connectors as well.

Reliability cost money though!
C.


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## CliffyP

MicknPat said:


> WP1234,
> 
> This appears to be a common problem with tanks fitted to motor homes.
> 
> On our RV the 50 gallon fresh water tank LED display shows:
> 
> 1/4 = Empty
> 1/2 =1/4
> 3/4 = 1/2
> Full = 3/4
> 
> But at least I know and can act accordingly. :wink:
> 
> Mick


Hi Mick  
When it full does it say 'for gods sake stop putting water in'


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## Sargent

Hi Clive thanks for the tip, we use this connector already on the chassis of the X250 for the rear lights as well as some double decker bus harnesses. Reliability is okay but terminals are a nightmare to fit due to the double locking feature, and oh yes they are very expensive. The vast majority of the connectors used under the vehicle now have water seals fitted to them, if not they are in locations where water is not present??

CliffyP, I am sure we could do this if the demand was great enough??

Best regards

Ian Sargent


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## tviall

Thank you to everyone for this thread.

I crawled under the van this morning, located the plug and cleaned it all. It was already wrapped up with insulating tape but this wouldn't stop the oxidisation of the connectors. I have now cleaned these up, sprayed with WD40 and all is well. To keep out water I have wrapped the plug up with rescue tape and then tucked the plugged away out of harms way.

Again, thanks to Sargent and everyone for their comments. Another reason to subscribe to this great site.

Tony


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## wp1234

Since sorting out my fresh water sensors with the help of Ian at Sergeant I now have a problem with my waste sensors. 
The gauge above the door is either showing 0% when empty or anything between empty and full then at overflow point it shows 100% i.e no other readings in between. 
Is there an easy fix I’m missing? or does anyone know how the sensors pick up the levels on an autotrail tank ? I’m thinking that the sensor heads are gunged up internally and if so some strong tank cleaner might do it ?
Thanks all


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## peribro

If yours is the same as mine, then this is correct i.e. there are only two readings - empty or full. I don't believe that Autotrail fits the 50% sensor. This is from the User Instructions for the EC325 control panel:

Display Description Options / Notes
Waste Water
0% Full
â-¼
Water level in the waste water tank
(2 measurement levels)
If the water pump power switch is
turned ON and the waste water
level rises to 100% a warning beep
will be heard and the LCD display
will flash. To cancel the warning,
press the select (â-„) button. The
warning will not be repeated unless
the water pump power switch is
turned off and on again. This is to
ensure the warning does not
become a nuisance.
0% < ½ Full
50% >= ½ Full (optional level
that is not normally fitted by
most manufacturers)
100% = Full


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## Sargent

Hi wp1234, peribro is correct, whilst the system can have a 1/2 or 50% indicator, unfortunatly your vehicle is not fitted with this sensor, it could be retro fitted but this would involve drilling a hole in the waste tank at the correct point, also running an additional wire to the EC325 PSU?

Best regards

Ian Sargent


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