No power to water pump

[Jofang]

First time out today for our Hymer B878SL for almost a year due to moving house. Arrived on site to find water pump not working, so no sink, toilet or shower. Checked all fuses under the dash one at a time with a meter and all good. Put meter on 12v feeding pump and got no 12v. Rotor in pump spins freely. Will have to return home if unable to fix. Help ideas please.

 

[Phill D]

i dont think the fuse for the pump is in the dash it is likely to be in the habitation distribution unit possibly an electro block.

 

[Spriddler]

Are other 12v items working (e.g. interior lights)?

 

[Lenny HB]

Pump fuse will be a 7.5 or 10 amp in the Elektroblock.
Have you tried all taps as as the micro switches or the wiring in the taps is a common problem.
I got fed up with them failing and fitted a Shureflo pressure switched pump.

 

[Jofang]

Everything else is working except the hydraulic jacks, which are also not working but they're run by the engine battery not habitation battery, so don't go through the van electrics.

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[Jofang]

Sink, toilet and shower taps not working as well as toilet flush.

 

[Emmit]

When you say "the rotor in the pump spins freely" do you mean that when coaxed with a finger it moves without resistance or do you mean that when you apply electricity to it, the impeller spins but doesn't supply the water at the tap or whatever.

 

[Phill D]

have you located the elecktrobloc unit with its fuses?

 

[autorouter]

Have you found the Elektroblock (EBL), a blue box with a white front panel. It has all the 12V habitation connectors and fuses on it. The pump is one of them, labelled something obvious like 'Pompe'.

As far as I know, Hymers have taps with microswitches in them, and no switch to enable the pump. But it might be the type of system with no microswitches in the taps, in which case it will have a switch somewhere to turn the pump on and off.

 

[Jofang]

When you say "the rotor in the pump spins freely" do you mean that when coaxed with a finger it moves without resistance or do you mean that when you apply electricity to it, the impeller spins but doesn't supply the water at the tap or whatever.

Hi Emmit, the pump rotor spins freely. It's not jammed or otherwise stuck.

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[Emmit]

For the last two 'Springs' after our Burstner was laid up for several weeks, I had to resort to sticking my hand in the tank and giving the submirsable pump a sharp slap against the side of the tank.
On both occasions, the pump started to, er pump.

 

[Jofang]

Have you found the Elektroblock (EBL), a blue box with a white front panel. It has all the 12V habitation connectors and fuses on it. The pump is one of them, labelled something obvious like 'Pompe'.

As far as I know, Hymers have taps with microswitches in them, and no switch to enable the pump. But it might be the type of system with no microswitches in the taps, in which case it will have a switch somewhere to turn the pump on and off.

Hi Phil and Autorouter,
Have not found electrobloc yet, as it's now dark here but have found its schematic (in french) and cannot see any reference to water pump but plan to meter all fuses on the block tomorrow. We have taps with switches but unlikely all 3 and toilet switch would fail simultaneously. I would expect the switches to operate the pump through a relay but can't see anything suitable on the schematic.

 

[autorouter]

The EBLs are sometimes well hidden. Mine is at the front under a cupboard with a sliding top door next to the driver's area. Slide back the door, lift out the plywood cupboard base, and there it is.

Which EBL is it? The manuals are usually available in English from the Schaudt website. Unfortunately it's in German, but not impossible to negotiate. On the Service-Support page, select EBL, (Bitte wahlen = please select). Select 'mit Ladefunction' (= with charger function). Select 'Anzeigertafel separat' (= separate display panel, ie not integrated on its front panel). Then click 'Artikel anzeigen' (= display articles) to show a very long list.

Find your EBL model, and click on the union jack symbol to select the English version. Click the 'Downloaden' button, then enter your email address. They send you a download link in an email, usually within a minute or two.

If you have the French version, look at the picture of the front panel, it should show the fuse for the pump.

 

[Jofang]

Thanks again Autorouter for your very valued message. I will certainly follow up the link you've given me for the UK manual. We're back home now, as my wife could not manage without water in the sinks, shower & toilet. First step will be to remove pump & apply 12v from slave battery to prove one way or the other, thereafter I'll move on to the power block, which is buried beneath the kitchen. But WHY bury it under the kitchen when there's loads of room in easy accessible cupboards? German engineering??? As well as the hydraulic levelling not working the drivers electric window has stopped working. Never a dull moment at our house.....

 

[Jofang]

The EBLs are sometimes well hidden. Mine is at the front under a cupboard with a sliding top door next to the driver's area. Slide back the door, lift out the plywood cupboard base, and there it is.

Which EBL is it? The manuals are usually available in English from the Schaudt website. Unfortunately it's in German, but not impossible to negotiate. On the Service-Support page, select EBL, (Bitte wahlen = please select). Select 'mit Ladefunction' (= with charger function). Select 'Anzeigertafel separat' (= separate display panel, ie not integrated on its front panel). Then click 'Artikel anzeigen' (= display articles) to show a very long list.

Find your EBL model, and click on the union jack symbol to select the English version. Click the 'Downloaden' button, then enter your email address. They send you a download link in an email, usually within a minute or two.

If you have the French version, look at the picture of the front panel, it should show the fuse for the pump.

My model is EBL 213.

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[Jofang]

The EBLs are sometimes well hidden. Mine is at the front under a cupboard with a sliding top door next to the driver's area. Slide back the door, lift out the plywood cupboard base, and there it is.

Which EBL is it? The manuals are usually available in English from the Schaudt website. Unfortunately it's in German, but not impossible to negotiate. On the Service-Support page, select EBL, (Bitte wahlen = please select). Select 'mit Ladefunction' (= with charger function). Select 'Anzeigertafel separat' (= separate display panel, ie not integrated on its front panel). Then click 'Artikel anzeigen' (= display articles) to show a very long list.

Find your EBL model, and click on the union jack symbol to select the English version. Click the 'Downloaden' button, then enter your email address. They send you a download link in an email, usually within a minute or two.

If you have the French version, look at the picture of the front panel, it should show the fuse for the pump.

I've located the EBL and have downloaded the manual as you suggest, which is great, however, there is no mention anywhere in the english version of the Schaudt manual or schematics of the water pump or any of the tap switches. My next approach is to try to trace the wiring to the water pump where it disappears under the kitchen. Wiring appears to be 1.5mm2 so it's quite meaty as opposed to all the signal wiring in and out of the EBL. If I can trace the wiring maybe I'll find a hidden fuse en route???

 

[Spriddler]

First step will be to remove pump & apply 12v from slave battery to prove one way or the other,

It isn't strictly necessary to remove the pump to do that provided that you can get at or near enough to connect the slave battery to the pump's own feed wires or terminals.

 

[autorouter]

This EBL 213 is not like most of the other EBLs. Instead of all the wires going to the front panel connectors, it has a distribution bus (SDT Bus) and several modules located at strategic points around the MH. There are special modules for the lights, door, signals and tank, and some general purpose modules.

The relevant module is the TAM213 Tank Module, detailed on page 12. Connector 8 is a 2-way plug labelled 'Pump'. Worth checking that to see if there's any power there. But first find the module.

 

[Guigsy]

I've got an EBL 630 which also has the odd module controllers and STDBus. I had a pump failure. I could not switch the pump to ON from the control panel. It turned out to be a control panel fault that required replacement. Thankfully under warranty because they are expensive!

I'm not sure, but I think that panel failed because it can't cope with low voltages. From reading other forums, it sounds like the memory can get corrupted.

 

[Jofang]

A huge vote of thanks, especially to Autorouter. I eventually found the problem - at some time in the past the previous owner must have replaced the water pump and used a section of strip connector to join the wires into the existing loom. Upon stripping this connection I found that the red wire had been inserted too far into the connector and upon tightening the screw had squashed the red outer plastic covering but had barely pierced it, making a very poor contact, so it's a wonder the pump ever worked. With a renewed connection done properly the pump is now working. I had hydraulic jacks fitted last year, which worked fine until yesterday. Again, a stupid problem by the dealer, the 25A spade fuse had not been pushed all the way into the fuse holder and eventually vibrated loose. The drivers door window failure was down to me. After checking all fuses with a meter in search of a problem with the hydraulic jacks I must have put the 7.5A fuse for the electric window back into a blank fuse slot, stupid! All is now working and we're back on the road again tomorrow morning.

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[MisterB]

A huge vote of thanks, especially to Autorouter. I eventually found the problem - at some time in the past the previous owner must have replaced the water pump and used a section of strip connector to join the wires into the existing loom. Upon stripping this connection I found that the red wire had been inserted too far into the connector and upon tightening the screw had squashed the red outer plastic covering but had barely pierced it, making a very poor contact, so it's a wonder the pump ever worked. With a renewed connection done properly the pump is now working. I had hydraulic jacks fitted last year, which worked fine until yesterday. Again, a stupid problem by the dealer, the 25A spade fuse had not been pushed all the way into the fuse holder and eventually vibrated loose. The drivers door window failure was down to me. After checking all fuses with a meter in search of a problem with the hydraulic jacks I must have put the 7.5A fuse for the electric window back into a blank fuse slot, stupid! All is now working and we're back on the road again tomorrow morning.

We've all been there, but the plus point is that you now understand your motorhome a lot more.