Skip to main content ↑ ↓
Topic: U280 water pump - not turning on (Read 763 times) previous topic - next topic

U280 water pump - not turning on

Greetings,
hope this is a fuze
turn on water pump... click from each location
no pump action...

I am checking voltage at the pump now
The selected media item is not currently available.
My advice and experiences are Free, you decide if they are worth anything .

John - driving Old Faithful
1994 U280 GV
C8.3, Banks, Pacbrake, 900 watts, Resonator, XLHD tow dolly
Retired Army Warrant Officer

Life is what you make of it - if it is lemons, make lemonade!
Former Coaches:
1988 GV 40' ORED 300HP CAT - 9 years
1990 Winnebago LeSharo - 3 years
2000 Newmar London Aire - 3 years (#18 of 23 produced)

Re: U280 water pump - not turning on

Reply #1 –
Water pump switches just controls a relay, ours mounted on bay wall behind white fiberglass cover.  Relay turns pump on & off.  Relay often clicks.  Find relay and measure voltages, and measure pump voltage.  If pump has good 12v & good ground and 12v turns on & off with switches, all switches & relay are ok, and problem is with pump.  What model pump do you have?  Does pump get hot?

Re: U280 water pump - not turning on

Reply #2 –
Thanks Barry....

I hate to tell this.....
while I was measuring voltage at yhe pump.... I was also filing the tank. Turns out pump
WILL NOT turn on if water level is toooo low.

I'm embarrased :facepalm:
The selected media item is not currently available.
My advice and experiences are Free, you decide if they are worth anything .

John - driving Old Faithful
1994 U280 GV
C8.3, Banks, Pacbrake, 900 watts, Resonator, XLHD tow dolly
Retired Army Warrant Officer

Life is what you make of it - if it is lemons, make lemonade!
Former Coaches:
1988 GV 40' ORED 300HP CAT - 9 years
1990 Winnebago LeSharo - 3 years
2000 Newmar London Aire - 3 years (#18 of 23 produced)

Re: U280 water pump - not turning on

Reply #3 –
John,

Have not seen that one.  How is tank level information conveyed to pump relay?

Would think with low water pump would run, but no water coming out.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: U280 water pump - not turning on

Reply #4 –
probably the incoming pressure kept was overriding the pump pressure switch keeping the pump from running.
previous 1984 35 ft ORED 250 HP 3208 Cat       
previous 1998 40 ft U295 CAI 325 hp Cummins
previous 2003 40 Ft u320 build #6140 450 Cummins M11.                                                         
1999 Mazda Miata
Ron, Nancy, Tipper the cat, Max The dog
1997 U 270 36 ft build number 5174 8.3 Cummins

Re: U280 water pump - not turning on

Reply #5 –
Quote from: red tractor –
probably the incoming pressure kept was overriding the pump pressure switch keeping the pump from running.

Interesting point. 

With pump cut in pressure of around 23 PSI, can't see how fill pressure (tank VENTED) could approach that. 

Said another way, if potable water tank pressure approached that, you would have an EXPLOSION of the plastic tank.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: U280 water pump - not turning on

Reply #6 –
The pump is tied into the pressure line that is filling the tank so the pump is not reading tank pressure but incoming water pressure.
previous 1984 35 ft ORED 250 HP 3208 Cat       
previous 1998 40 ft U295 CAI 325 hp Cummins
previous 2003 40 Ft u320 build #6140 450 Cummins M11.                                                         
1999 Mazda Miata
Ron, Nancy, Tipper the cat, Max The dog
1997 U 270 36 ft build number 5174 8.3 Cummins

Re: U280 water pump - not turning on

Reply #7 –
Interesting theories on both sides.

As far as I know, the diameter of the water line "in" is the same all the way to the tank.  Can't see a big delta in pressure through the system.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: U280 water pump - not turning on

Reply #8 –
To help understanding of this issue think about what happens if you leave the tank fill valve open, and the pump will continue to run until you turn the fill valve off, so definitely incoming pressure will effect the pump pressure switch.
previous 1984 35 ft ORED 250 HP 3208 Cat       
previous 1998 40 ft U295 CAI 325 hp Cummins
previous 2003 40 Ft u320 build #6140 450 Cummins M11.                                                         
1999 Mazda Miata
Ron, Nancy, Tipper the cat, Max The dog
1997 U 270 36 ft build number 5174 8.3 Cummins

Re: U280 water pump - not turning on

Reply #9 –
Quote from: red tractor –
The pump is tied into the pressure line that is filling the tank so the pump is not reading tank pressure but incoming water pressure.
That is correct and either a solenoid or manual valve allows the tank to fill. If you open fill valve, pressure drops, [water is dumping into tank] and pump will see low pressure and run. If tank fill valve closed, pump will see shore water pressure and probably not run.
Nothing to do with tank level.
Jim C.
coachfree, previous 1997, 1999, 2000, and 2003 Foretravels.

Re: U280 water pump - not turning on

Reply #10 –
Possibly had the fill valve only partially open? enough restriction to water flow (if high pressure 60 - 80 psi on the supply line from water source) that over 20 psi was at the pump?
Just a SWAG.................
Justin & Cathy Byrd
1995 U280 "Old Faithful"
36' Build #4673
C8.3 Cummins
Allison MD3060R 6 speed - retarder
Powertech 10KW  4cyl Kubota

Re: U280 water pump - not turning on

Reply #11 –
Thanks Guys... I feel real silly.

The facts are as soon as I put some water in.. I shut evert hinges from the house offf, valve closed.. it worked.

Said another way, pump relay from each swithch.. clicked..no pump
. looked at monitor..E... filled for 5 minutes, still on E.. but water pressure ! Pump worked, FILLED TANK 

All is good, sorry to take valuable time...  ^.^d
john
The selected media item is not currently available.
My advice and experiences are Free, you decide if they are worth anything .

John - driving Old Faithful
1994 U280 GV
C8.3, Banks, Pacbrake, 900 watts, Resonator, XLHD tow dolly
Retired Army Warrant Officer

Life is what you make of it - if it is lemons, make lemonade!
Former Coaches:
1988 GV 40' ORED 300HP CAT - 9 years
1990 Winnebago LeSharo - 3 years
2000 Newmar London Aire - 3 years (#18 of 23 produced)

Re: U280 water pump - not turning on

Reply #12 –
We are all always learning something new.
previous 1984 35 ft ORED 250 HP 3208 Cat       
previous 1998 40 ft U295 CAI 325 hp Cummins
previous 2003 40 Ft u320 build #6140 450 Cummins M11.                                                         
1999 Mazda Miata
Ron, Nancy, Tipper the cat, Max The dog
1997 U 270 36 ft build number 5174 8.3 Cummins