# Grey Waste Tank Sensor



## grahamb47 (Jun 6, 2006)

On my Autoroller there is a light on the control panel for the full waste tank warning, but it has never worked. There looks to be 2 tags on the tank but don't seem to connected.
Help would be appreciated as we often overflow water onto the pitch.


----------



## 88927 (May 10, 2005)

Hi grahamb47
Have you looked under the van for two wires not connected to anything mate? I would suspect that they have been ripped off at some time, which is why the indicator isn't working :lol: 

Good luck

Keith


----------



## elbino (May 9, 2005)

Had a similar problem on my Autotrail.The sensor was just a push fit into the tank about 2/3 up and was a simple arm and float connection that completed the circuit as the water rose. Somehow the unit had been twisted in the seating about 90 degrees so that the float part could not hang down as required and a build up of sludge prevented any contact between the two parts. A quick clean and reseating in the correct manner solved the problem in 2 seconds.Also noticed that the wires leading from the sensor were not protected so a quick clean of the contacts and some insulating tape around any connectors has eliminated further occurrence (touching wood) . My problem is that fresh water tank gauge has to be reset at every reading......which is fine when you know its full but after a couple of days what level can I reset it too without knowing how much water is in the tank ..which is why you have a gauge in the first place...


----------



## rickwiggans (May 10, 2006)

I had exactly the same problem with my Swift. The wires were broken, and once repaired, works fine. You will probably find the two ends somewhere nearby, although if not immediately apparent, they may have broken off inside a nearby wiring loom - that's where I found mine. Make sure you get them the right way round when you reconnect - your wiring diagram should help identify which is which


----------



## G2EWS (May 1, 2006)

Hi grahamb47

As mentioned you will likely as not find wires disconnected. Start at the waste tank and you may find some wires connected via nuts and bolts and possibly some resistors between. If these are connected you will have to track the cabling back.

Regards

Chris


----------



## grahamb47 (Jun 6, 2006)

*grey waste sensor*

had a look at the tank & the wires seem to be screwed into two plastic studs about 4 inches apart but the screws do not pass through into the tank!!!!!


----------



## G2EWS (May 1, 2006)

Hi grahamb47,

I cannot be certain but sounds as though you have a system that will work totally inside the tank. This will comprise of a strip with a float that has a magnet in. The float will pass over a resistive network. The resistive network will then be a representation of the level in the tank.

The screws you see will almost certainly be connected to this system on the inside of the tank.

Suggestions:

1. The bit inside the tank has come off - drastic so dont think along those lines straight away.

2. As mentioned by others the cable has been severed/disconnected somewhere in the route. This is normally (big word!) a simple job of tracing the cable which for most of it's journey will be by itself.

3. The display instrument has a fault. This again can be simple if you can get behind it.

Any one of the three above can be checked using a multimeter set to ohms with power disconnected to the system. At the tank you should have a few k ohms (again normally but I have seen a system with only a few ohms!) which will change with changing water level. If you take a long lead and connect between the tank and the instrument panel you should se a short. If either wire is not a short you have a broken lead.

I hope that is simple enough to understand, if not let me know and I or someone else will go deeper.

Regards

Chris


----------



## eddied (May 9, 2005)

*Waste water tabk sensors*

 
I too have a problem with mine. When empty, shows full, then when some waste runs into tank, warning light goes out. Comes on again when tank getting full. I can live with this as long as I can remember whether or not I recently emptied tank.
Chris your answer is really good, but me being me and my knowledge of electrics being what it is, I certanly wouldn't want to go any deeper. The habitation checkers can do that.
saluti,
eddied


----------



## grahamb47 (Jun 6, 2006)

*Grey Waste Sensor*

Hi, thanks for all the advice.
I have attached a photo of the side of the tank, the van floor at the top.
You can see the two studs with the wires on. The screws do not penetrate the tank. The large threaded hole in the plastic does not go right the way through. I cannot see anyway in which this would work, is there something missing?


----------



## Mat7 (May 15, 2005)

I would try shorting the pair of wires to see if it make the waste tank full warning come on.

It could be a case that the fittings are there but no sensor installed.

Cheers Matt :roll: 8O :roll: 8O


----------



## grahamb47 (Jun 6, 2006)

*Grey Waste Sensor*

Sorry, yes I forgot to mention I did short the wires out and the light on the control panel comes on.


----------



## Mat7 (May 15, 2005)

*Re: Grey Waste Sensor*



grahamb47 said:


> Sorry, yes I forgot to mention I did short the wires out and the light on the control panel comes on.


So I would call it safe to assume that the sensor is not in installed, and that you could take this issue up with the dealer you got the motorhome from. or approach someone like CAK tanks for advice on a suitable sensor.

Cheers Matt  :roll:  8O


----------



## grahamb47 (Jun 6, 2006)

*Grey Waste Sensor*

Thanks for your advise Matt.
I bought the van second hand,private sale.
Maybe the sensor was never fitted at manufacture.
It would be handy if another Rollerteam or C.I. owner could verify that their sensor works OK.

Thanks, Graham


----------

