Water pump not working (1 Viewer)

[Pedroskie]

Hi everyone, I have a problem with the internal water pump for my MH. For some reason my waterpump has stopped working, I replaced with a new one but still have the same problem, I checked that when one of the taps(micro switches) is turned on that I get 12volts at the wiring to the pump(wires are pink and brown) but the pump still doesn't work. The pump works off an external 12 volt supply but unfortunately not when I connect back up normally. Could it be a current issue? Any help would be much appreciated. Thanks

 

[Vaman]

Check the voltage at the pump whilst the tap is turned on, also try other taps such as shower if that uses the same pump. If voltage drops then you have a high resistance in the line limiting the current. You could then bypass your switch using a piece of wire to eliminate that being the fault. Also check the fuse holder for the pump supply and confirm the fuse is tight and clean. HTH

 

[Pedroskie]

Check the voltage at the pump whilst the tap is turned on, also try other taps such as shower if that uses the same pump. If voltage drops then you have a high resistance in the line limiting the current. You could then bypass your switch using a piece of wire to eliminate that being the fault. Also check the fuse holder for the pump supply and confirm the fuse is tight and clean. HTH

Hi I've checked the voltage on the wires that connect to the pump while it's disconnected, I get a steady voltage with all the taps on or individually turning them on. Checked the fusel at the EBL99, all seems OK?

 

[Lenny HB]

Try reversing the wiring to the pump normally they just run slower if revered.
On Hymers the the pump wires are the opposite colours to the loom they connect to.

 

[Vaman]

Ah, the old swap wire trick, a bit like Maxxair! Certainly worth a look.

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[Pedroskie]

Check the voltage at the pump whilst the tap is turned on, also try other taps such as shower if that uses the same pump. If voltage drops then you have a high resistance in the line limiting the current. You could then bypass your switch using a piece of wire to eliminate that being the fault. Also check the fuse holder for the pump supply and confirm the fuse is tight and clean. HTH

Hi sorry I also meant to say with it all connected as normal I don't see 12volts at the pump when a tap is turned on? Only see 12 volts with pump disconnected, on the wires that normally connect to the pump. But the pump does work with an external 12 volt supply? Thanks Vaman

 

[Vaman]

Does the voltage drop to zero with the tap on?

 

[Pedroskie]

Does the voltage drop to zero with the tap on?

Hi Vaman I only seem to see a voltage(on the wires that normally attach to the pump)when the pump is disconnected and I operate one of the taps? Which is why I thought it was the pump but as I said even the old pump that I took out, because I thought it was faulty works on an external 12volt source?

 

[Pedroskie]

Try reversing the wiring to the pump normally they just run slower if revered.
On Hymers the the pump wires are the opposite colours to the loom they connect to.

Hi Lenny, the old pump I took out just stopped working, I haven't used the van for a while, only just realised a few days ago. But if I connect the old pump up to an external 12volt source it works fine? I'll try a wire reversal tomorrow but the thing is it always used to work the way it was connected before? The MH is a fiat burstner T-625. Thanks

 

[BouncyBoatFolk]

Is it a submersible pump?
If so, it could be water in loom, or a broken wire.
Also, pull an replace the fuse, that could have a poor connection.
Mike.

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[Vaman]

One side of the pump will go to negative (I assume it is the positive wire that switches it on and off). If so connect the positive supply to the pump postive, turn on the tap and substitute the negative wire with a piece of wire to a negative connection, all the way to the hab battery negative if necessary. If no pump then we have eliminated an earth fault. The fault lies with the switch or positive supply. Pumps are quite high current so you may get a spark or two, do not worry, if correcting the issue then you will hear the pump run briefly.

Also try the above but touch the original negative connection on and off of the pump connect, if you see even a tiny spark then you have a supply but it is current limited due to high resistance somewhere (switch or supply connections).
Question:-
Does your MH have a rocker switch for the water pump supply,
Please DO NOT ATTEMPT this if you are not comfortable. ENSURE YOU ARE DISCONNECTED FROM THE MAINS SUPPLY BEFORE undoing the panel.

if happy to do so, connect everything back up, turn on the taps and get to the back of the rocker switch, move the wire around I suspect a failed rocket switch could be the problem, you could also short across the switch pair to eliminate the possibility of a faulty switch.


Do you have a multi-meter, and if so do you know how to use it. It would be very useful to know what voltage the supply drops to on your test. For example either side of the main switch.

 

[donkey]

So, there is 12v at the pump wiring, which drops to zero when pump is in circuit??
Likely to be faulty connections, poor connections, a relay if one is in the circuit, a fuse that is corroded or poorly connected, multi connector at power supply.
Best way to check is work back from pump with a 12v test lamp, have the taps open and pump connected. You will eventually come to a good supply which will light the test lamp full brilliance.

Geoff