My water pump, Shurflo, in my 2007 Fleetwood (popup) blows a fuse (10A blade/inline fuse) when plugged into shore power but runs fine on 12V. Everything on 110V works fine, except the water pump. The ONLY thing different is I replaced two six volt batteries with one 12 volt battery. Nothing else has changed since the last time had the trailer popped up.Suggestions?

Does your rig have multiple momentary switches to operate the pump?It could be the "pump controller" causing the issue.Corroded connection could increase resistance and over load the fuse.Check the converter output voltage.

The water pump operates only on 12vdc. Shore power is 120 volts AC. If your trailer battery is low on charge the pump will pull more current and may blow the fuse.

sljkansas wrote:The water pump operates only on 12vdc. Shore power is 120 volts AC. If your trailer battery is low on charge the pump will pull more current and may blow the fuse.X 2

That's funny. I told the wife I thought the same thing, theoretically, could happen (not knowing any different) and I was going to see if leaving the shore power hooked up to charge the battery made a difference. It did. Works fine now. Thanks for all your help.

Replacing the two 6v batteries (220 amps) with one 12v battery (65 to 85 amps) is going to be a mistake. One 12 volt battery will need more time to fully recharge than the 6v pair of batteries.It sounds like you have not kept the battery on shore-power long enough to fully recharge (24 to 48 hours). Have you used the "disconnect" switch to make sure the battery when fully charged does not lose charge due to detectors, CPUs in equipment, etc. drawing current while stored.Having a smaller battery-bank can easily deplete the battery if you forget to disconnect when stored. If leaving plugged in all the time, be prepared to check the battery cells for lost fluid.

Water Pump - 12V works, 110V blows a fuse | Good Sam Community

18 Replies

mkirsch
Nomad II
Sep 08, 2015
The reason it works fine now is because the converter is no longer charging the battery. Run the battery down some and try again while the converter is in charge mode, and the problem will return.

The pump is getting dodgy. You'll have to determine for yourself if replacing the pump is worth it.
MEXICOWANDERER
Explorer
Sep 08, 2015
Like trying to read Sanskrit...

"but everything works fine now."

So self-correction. End of issue....
Ace_
Explorer
Sep 08, 2015
Nope, inline fuse solely for the pump, but everything works fine now.
BFL13
Explorer II
Sep 08, 2015
Ace! wrote:
I put the two six volts when I was boondocking, a few years ago (or more). They needed to be replaced so I decided to go back to one 12V, which the "new" owner will better understand. I had just put the (one) battery on the trailer and started to see how stuff worked.

When I turned on the refrigerator the fan came on for the converter (overload/overheat fan). That's also when the fuse for the pump blew. If I unplugged the shore power everything in the trailer worked fine. After a few hours of leaving the popup hooked to shore power (charging the battery), everything worked on shore power, including the water pump.

I can see how a 12v fridge might cause the converter to run hard but not run so hard when the batts are charged up to help run the fridge. Not many fridges are 12v anymore though. Most now just need a little 12v to run the controls and propane burner.

Is the 10a fuse that blew also to do with the fridge somehow? Fridge plus water pump too many amps? This all may have nothing to do with the water pump itself.

Just guessing. No idea what is actually going on there.
enblethen
Nomad
Sep 08, 2015
The pump could have some type of restriction in the lines that requires the pump to work harder. Could be debris in the faucet aerators.
red31
Explorer
Sep 08, 2015
A 7A RV water pump blowing a 10A fuse sounds like the pump is going, but it ain't gonna be your problem once it leaves the drive way !
Ace_
Explorer
Sep 08, 2015
I put the two six volts when I was boondocking, a few years ago (or more). They needed to be replaced so I decided to go back to one 12V, which the "new" owner will better understand. I had just put the (one) battery on the trailer and started to see how stuff worked.

When I turned on the refrigerator the fan came on for the converter (overload/overheat fan). That's also when the fuse for the pump blew. If I unplugged the shore power everything in the trailer worked fine. After a few hours of leaving the popup hooked to shore power (charging the battery), everything worked on shore power, including the water pump.
MEXICOWANDERER
Explorer
Sep 08, 2015
An RV battery delivers what, 12.4 - 12.5 volts under an 8-amp water pump pressure build-up.

The voltage difference 12.4 - 14.4 absorbsion limit is TWO FULL VOLTS. Divide 14.4 into 12.4

How much percentage GAIN is there with using higher voltage?

This deserves troubleshooting with an inductive ammeter. The pump may be sick.

Find the cause soon and perhaps the pump can be successfully repaired. Find it later and guaranteed a new pump will be required. After a waterless outing.
red31
Explorer
Sep 08, 2015
BFL13 wrote:

This is not over IMO---why did that fuse blow?

Mex explained it but not enough info, what if it was blowing when the WFCO actually was doing 14+ and didn't blow at 13.6 or batt v?
MNtundraRet
Navigator
Sep 08, 2015
Sorry. I missed the fact you had a popup trailer. You might have a wire somewhere in the charging circuit that may be frayed and shorting causing the fuse to blow.

And one battery should be enough for your trailer. It sounds like the previous owner set up the trailer for two batteries. Wires going through the trailer walls may have frayed if a proper grommet was not installed to protect them.