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Topic: Water fill valve auto shut off/Gems water level sensor (Read 836 times) previous topic - next topic

Water fill valve auto shut off/Gems water level sensor

Has anyone had to service or replace this switch?  Any idea if this should be wired as a n/o or n/c circuit?  I'm trying to undo a previous "repair" which has somehow put the water pump on the water fill valve circuit.  Any help would be appreciated.
George Mann
2002 U320 #5934
2017 Rubicon
2013 BMW GS
Waterford MI

Re: Water fill valve auto shut off/Gems water level sensor

Reply #1 –
If your coach is like mine you have 2 latching relays beside each other in the bay behind
the with cover. One is for the fill and the other is for the pump so that is were I would look.
The relays are N/O. 
Peter and Frieda Morin
1999 36ft. U320 Foretravel
Build # 5436
1998 Suzuki Sidekick Sport

Re: Water fill valve auto shut off/Gems water level sensor

Reply #2 –
I don't have the two (Finder) latching relays that others have located behind the big fiberglass cover in the basement bay with the 12 volt circuit breakers.  The electrical diagram shows the two relays for the water pump and the water fill valve but also includes the note: "exc 4200".  My understanding is that the 42' models (at least in 2002) include the Intellitec lighting controls which also include the water pump and water fill switches.  The Intellitec control modules are located in the cabinet under the refrigerator and I'm assuming that the they also perform the function of the latching relays that I don't have.  Can anyone confirm this?  This would make sense because I have also discovered that the 12 volt circuit breaker B29 which is labled "water pump" does not have a wire connected to it.  The only other possiblity is that someone has altered the wiring which is also likely since the whole reason I'm trying to figure this out is because someone has previously replaced the water pump and somehow wired it to the water fill circuit and also they had eliminated the water fill valve and changed it to a manual fill.  I have since replaced the water fill valve and am now trying to sort this wiring out and get it back to original.  Any information on this topic is appreciated.
George Mann
2002 U320 #5934
2017 Rubicon
2013 BMW GS
Waterford MI

Re: Water fill valve auto shut off/Gems water level sensor

Reply #3 –
Well 3 years have gone by and I find myself deep in the plumbing bay once again.  I never solved this problem and I would really like to get this sorted out.  Here's what I know; my 2002 coach has the Intellitec light switches which also control the water pump and water fill valve so I don't have the Finder latching relays that other coaches have.  There are four wires on the curb side of the wet bay; one is energized when the water pump button is pushed, one is energized when the water fill button is pushed and the other two are green ground wires (presumably one each for the pump and fill valve).  There are two green wires on the road side of the wet bay; one is energized when the water pump button is pushed (so there are two wires energized by that switch) and the other wire goes back over to the curb side (a fifth wire on that side).  I have replaced the overflow float switch because the original was removed by a previous "RV technician" who also removed the electric fill valve and replaced it with a manual valve.  In order to figure out the wiring I need to know if FT installed the float switch as a normally open (which would close the circuit when the tank is full) or normally closed (which would open the circuit when the tank is full).  I think the float switch can only be installed as normally open because this orientation has the float hanging down and it floats up to the horizontal position closing the circuit.  If you turn the float switch 180 degrees it will act as normally closed but then the float is normally horizontal and has to float up to open the circuit but I think it's too close to the top of the tank and it would hit the top of the tank before opening the circuit.  Wiring for a normally open switch is more difficult because you would need to interrupt power to the valve by closing a control circuit and I'm not sure how to accomplish that.  Last thing that I would add is that I think the same RV technician may have crossed the pump and fill valve wires at the relays because they have relabled the wires, swapping those two circuits.  This means that either the pump switch can energize two wires (one on the curb side and one on the road side) or if the wires are swapped back, the fill switch will be the one that energizes the two wires.
Sorry for the lengthy post but this is proving to be a very difficult riddle to solve.  If anyone with knowledge of a 2002 era 42' coach with Intellitec switches can provide some info on how these are wired I would be very grateful.
George Mann
2002 U320 #5934
2017 Rubicon
2013 BMW GS
Waterford MI

Re: Water fill valve auto shut off/Gems water level sensor

Reply #4 –
adding this crude diagram to help illustrate my problem.
George Mann
2002 U320 #5934
2017 Rubicon
2013 BMW GS
Waterford MI

Re: Water fill valve auto shut off/Gems water level sensor

Reply #5 –
In your drawing the float is accessible from the road side?

On the road side you only; have two wires, 12V switched marked "Pump" and the green that goes to the curb side. Is this correct? 
You are sure the curb side 12V is coming from the water pump switch? 
Do you have a spot where you could supply a ground on the road side?
Is it possible to run a wire from road to curb side?

On the curb side you have  1 green wire that comes from the road side and two other greens that are grounded?

Wiring up the water pump is easy since it has nothing to do with the water fill.  Take the water pump positive  (+) and connect to your wire marked 12V SW pump, then take the ground and connect to the ground on the pump motor (-)


Update:  I just reread your post about the road side wire. So it is possible to rewire that wire to be positive for water fill instead of water pump?

Water Fill
First I would verify with a continuity meter where the float switch goes from open to close.  Is is level, above or below the level point of main control part of float.?  Is there some way to adjust the level, via a screw or bending of the rod?  Does the float have any ratings as to how much current  (Amps or Watts) it can take?
Need to verify if the float can or can not be used upside down where float switch is open when water level is low. It will be easier to wire with less chance of something screwing up but is doable with a simple relay as long as we can get a ground at the road side.




2014 ih45  (4th Foretravel owned)
 1997 36' U295 Sold in 2020, owned for 19 years
  U240 36' Sold to insurance company after melting in garage fire
    33' Foretravel on Dodge Chassis  Sold very long time ago

Re: Water fill valve auto shut off/Gems water level sensor

Reply #6 –
In your drawing the float is accessible from the road side?

On the road side you only; have two wires, 12V switched marked "Pump" and the green that goes to the curb side. Is this correct?  You are sure the curb side 12V is coming from the water pump switch?

On the curb side you have  1 green wire that comes from the road side and two other greens that are grounded?

Wiring up the water pump is easy since it has nothing to do with the water fill.  Take the water pump positive  (+) and connect to your wire marked 12Vsw pump, then take the ground and connect to the ground on the pump motor (-)

Water Fill
First I would verify with a continuity meter where the float switch goes from open to close.  Is is level, above or below the level point of main control part of float.?  Is there some way to adjust the level, via a screw or bending of the rod?  Does the float have any ratings as to how much current  (Amps or Watts) it can take?
Need to verify if the float can or can not be used upside down where float switch is open when water level is low. It will be easier to wire that was with less chance of something screwing up but is doable.
2014 ih45  (4th Foretravel owned)
 1997 36' U295 Sold in 2020, owned for 19 years
  U240 36' Sold to insurance company after melting in garage fire
    33' Foretravel on Dodge Chassis  Sold very long time ago

Re: Water fill valve auto shut off/Gems water level sensor

Reply #7 –

Just reread your post, so it is possible to rewire the road side pump switch 12V wire to water fill?  If so then finding a ground is not needed on road side.

If you determine that the float needs to stay the way you have it (open until full) then this relay should do the trick

Amazon.com: Hamolar 2 Pack 12V 40/30 Amp Car Relay DC 5 Pin SPDT and Harness...

Based on changing the road side wire to be a 12V + for water fill and float circuit closes when water level is full.  Here is how you need to connect the wires.
Road side
Take both the green wire coming from curb side and the 12V sw  and connect to two terminals on float.

Curb Side
Ground wire to white wire of relay
Green wire from Road side to Black of relay
12V Water fill from coach to Blue of Relay
Red from relay to positive of water fill valve
Ground from water fill valve to coach ground.


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2014 ih45  (4th Foretravel owned)
 1997 36' U295 Sold in 2020, owned for 19 years
  U240 36' Sold to insurance company after melting in garage fire
    33' Foretravel on Dodge Chassis  Sold very long time ago

Re: Water fill valve auto shut off/Gems water level sensor

Reply #8 –

This is the float switch that I bought:
Amazon.com: DC0-110V Liquid Water Level Sensor, Sensor Switch, Male Thread...
The OEM switch was a Gems sensor switch.  Finding a ground wire is not a problem as there are plenty of places to catch ground.  Mainly I'm trying to figure out how the factory wired this set up with the existing wires.  What I don't know is if they set it up so that the float switch was normally open or normally closed and I don't know if they used the float switch to make or break a ground connection or make or break a 12 volt connection.  I only have the ends of the wires to go by because the wiring all disappears into the "belly of the beast" so I cannot trace it back.  I am a little curious about how one of the switches will energize two wires; one on each side of the wet bay.  This implies that they are tied together somewhere that I cannot access.  I also don't understand why they would do that unless the intent was to energize the fill valve and the float switch at the same time.  I also don't fully understand how the Intellitec system works so that could have something to do with my problem.

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George Mann
2002 U320 #5934
2017 Rubicon
2013 BMW GS
Waterford MI

Re: Water fill valve auto shut off/Gems water level sensor

Reply #9 –
See my post #7 as to how to wire up relay. I was modifying my post and got side tracked before I reposted.
2014 ih45  (4th Foretravel owned)
 1997 36' U295 Sold in 2020, owned for 19 years
  U240 36' Sold to insurance company after melting in garage fire
    33' Foretravel on Dodge Chassis  Sold very long time ago

Re: Water fill valve auto shut off/Gems water level sensor

Reply #10 –
Quote from: Geodmann –
I also don't fully understand how the Intellitec system works so that could have something to do with my problem.

This is a very simple system.  You have your two modules that are the switches for your lights, water pump and water fill valve. Just thing of them as regular switches. on the wall. These modules get there input form the switches you have around your coach that then cause the module to supply power to the different "CR"
2014 ih45  (4th Foretravel owned)
 1997 36' U295 Sold in 2020, owned for 19 years
  U240 36' Sold to insurance company after melting in garage fire
    33' Foretravel on Dodge Chassis  Sold very long time ago

Re: Water fill valve auto shut off/Gems water level sensor

Reply #11 –
You've solved it!  So I just need to add the Bosch relay.  It's possible that a relay was removed when the fill valve was eliminated or it's also possible that the relay already exists; either in the Intellitec module or with the other relays in the electrical panel of the coach.  I'm going to experiment with my wiring a little bit more but now I know how I can make this work correctly.  Thank you for your help!!!
George Mann
2002 U320 #5934
2017 Rubicon
2013 BMW GS
Waterford MI

Re: Water fill valve auto shut off/Gems water level sensor

Reply #12 –
Quote from: Geodmann –
You've solved it!  So I just need to add the Bosch relay.  It's possible that a relay was removed when the fill valve was eliminated or it's also possible that the relay already exists; either in the Intellitec module or with the other relays in the electrical panel of the coach.  I'm going to experiment with my wiring a little bit more but now I know how I can make this work correctly.  Thank you for your help!!!

VERY IMPORTANT!!!!
Make sure you change the wire on road side where it has 12V when water fill is turned on and not water pump. If you can not do that then we just need to wire up the float switch a little different and connect the wires at the relay a little different.
2014 ih45  (4th Foretravel owned)
 1997 36' U295 Sold in 2020, owned for 19 years
  U240 36' Sold to insurance company after melting in garage fire
    33' Foretravel on Dodge Chassis  Sold very long time ago

Re: Water fill valve auto shut off/Gems water level sensor

Reply #13 –
Just circling back to close out this topic.  After a few years of stewing over this problem I have finally solved it with the help of the forum.  The float switch in the water tank is in fact wired as normally open and when the water level rises it closes the circuit which provides a ground path to the energized wire which triggers a relay to open the circuit to the fill valve.  Turbojack was correct when he suggested adding a Bosch style relay to make the system work but it turns out that relay is already in the system.  I could hear it click when I shorted out the 12 volt wire to the float switch and I think (but I'm not certain) that it's in the Intellitec module.  The main reason that I struggled to resolve this problem (and I'm pretty OK with electrical troubleshooting) is because someone (RV tech) had swapped the water pump and the water fill valve wires at the Molex connectors at the main Intellitec modules.  When I examined the wires closely (with an 8x loupe) I could see that the wires were labled IPX9 and IPX10 and they were connected to relays at the module numbered 10 and 9 (swapped).  I had to order a Molex pin removal tool to swap them back correctly and then everything else fell into place.  The system works as designed; I can hook up the water hose, turn on the auto fill valve and get distracted doing something else... when the tank is full the valve closes.  Perfectly elegant.
In the process of correcting this problem I also relocated my overflow drain hose as many others here have recommended and I will cover that in a separate topic.
Thank you so much to the forum for the invaluable help solving so many of the problems I have had with this adventure.  I'm truly grateful and don't know how this would be possible without the support of this forum.
George Mann
2002 U320 #5934
2017 Rubicon
2013 BMW GS
Waterford MI

Re: Water fill valve auto shut off/Gems water level sensor

Reply #14 –
That's what makes this the BEST forums, bar none!
Richard & Betty Bark & Keiko our Golden Doodle
2003 U320T 3820 PBDS
Build # 6215
MC # 16926
2016 Chevrolet Colorado 4X4 diesel