water pump wont stay on

[David T. Richelderfer]

One would think the latching relays for the water pump and shore water valve (red hat valve) would be in close proximity.  The kitchen switch for my shore water valve has been disabled in favor of having the only other switch operative in the water bay.  I have no idea where the latching relay for the shower water valve is but I have not spent much time looking for it.  Is it in the compartment along with the water pump's latching relay?

[Bill Lampkin]

On our coach, the shore water fill valve (red hat valve) is controlled via the aladdin tank level module. I had to jumper the wire connector at the module to allow the fill valve to work when the tank level module failed.

[Fred Brooks]

   Rick, enclosed are some pictures and the schematic of the "run relay" and the "latching relay". Here is the PCR to get you to the finish line. Problem: water pump will not stay on and run. Cause: diode has an open circuit or disconnected wire between terminal 86 or 87 on the "run relay". Repair: replace diode or repair continuity between terminals 86 & 87 on the run relay. Here is the relay logic: terminal 30 is 12volt supply to relay. 86 is 12volt to activate relay coil. 85 is the ground to complete coil circuit. 87 is connected to 30 when relay is Not activated. 87A is connected to 30 when the relay is energized.
I did not see 2 relays together in your picture but they must be somewhere close by. Fred

[Eric Maclean]

Fred
That's a very nice schematic drawing are you sure you weren't a draftsman in a previous life .
The lettering is a dead giveaway. LOL

Eric

[Fred Brooks]

  Eric, Mechanical Engineering 1968 @El Camino College Torrance California. Thanks for the kind words & Merry Christmas!

[Rick Daniels]

 Very informative info Fred Brooks.  In search of the second relay, using your diagram as a guide, I followed wires from the visible and recently replaced relay. It appears as though at least two of the wires from the known relay pass through a hole in the wall into the water bay itself, next to the grey tank. There I found can of worms of wires as if they were just shoved through the hole from the water pump side as reflected in the photo.  This was obviously not professional or factory job.  Amongst the can of worms of wires in the water bay I found a small flat object that at least one of the wires from the know relay goes into with wires coming out the same end.  It does not resemble a relay at all. It is wrapped in electricians tape.  Could this be something like a diode or relay.  Access is blocked by water lines coming from the manifold which will make it impossible to get at without removing the entire manifold.  To add insult to injury, we are expecting temperatures as much as-38 below zero starting tomorrow until Christmas. Then we get 40 degrees above.  Is there anyway you might know of that I can bypass all the systems and rig the water pump to turn on and off independent of  all relays and diodes and remote switches to get by for just a few days.  Anyway have a Merry Christmas. 

[Bill Lampkin]

You could bypass the relays by finding the black and red wire that go to the pump. Run the black wire to a good ground and run the red wire (with an inline 10a fuse) to 12v+. The pump has a pressure switch that will turn on the pump when any faucet is open.

[Rick Daniels]

Thank you Bill Lampkin.  I'm off to the parts house.  Merry Christmas

[Fred Brooks]

  Rick,
It is starting to look like someone who did not understand what he was looking at got creative. Enclosed is a picture of the diode after I cut the FLAT heat shrink off that enclosed it. As you can see, it has the blue and red wires.
  To perform a temporary repair, find the 2 red wires that are 12volt positive. (if you can't find them, find 1 red that is 12volt positive. Connect it to the water pump red wire with a wire nut. Find a white ground wire and connect it to the water pump black wire. The pump should now run when a faucet is opened. Please keep in mind this is Temporary!!!  Fred

[Rick Daniels]

Will the fill switch for city water to fill my tank still work? I cant stay hooked to city water other than to fill as the hose freezes and the supply is to far away for a heated hose.

[Fred Brooks]

   Rick,
 I would give it a try and see if it works. Did it work before?

[Rick Daniels]

Yes the fill switch did work before.  I think I will wait to continue this challenge until after Christmas.  There will be a 75 degree temperature increase between wednesday night and Christmas day. Thank you Fred and Bill for all your help.

[Rick Daniels]

reliable water flow via onboard water pump is still elusive.  sometimes it works sometimes not.  In trouble shooting the issue I determined that when an attempt to turn on the water pump works, an adjacent mounted solenoid clicks simultaneously with the pump turning on.  If that solenoid does not click the pump does not turn on. Result no running water.  Does anyone know what function that solenoid plays and is it possible my problem is a bad solenoid.  Photo attached.

[Fred Brooks]

   Rick, someone has added the solenoid to replace the original engineering. Conventional wiring of an 80 amp solenoid is as follows: The 9:00 post is 12volt power in. The 3:00 post is 12volt power out. The little post (red wire)? is the trigger post that activates the solenoid so long as it has continuous 12volt power. The other little post is the ground connection. Fred

[Bill Lampkin]

Kinda overkill for a water pump; If my memory serves, the water pump only draws 7 amps. Jumper the 9:00 post to the 3: post, the pump then should operate from its own pressure switch (if you have bypassed the relays as I previously suggested).