Loss of 12V Habitation Supply (1 Viewer)

[bigtwin]

I'm in France with neither my DVM nor my electrical schematic diagram, hence my plea here! And I'm usually pretty good at making sure that I have EVERYTHING I need - typical!

Woke up this morning to discover that we had no 12 V supply to the habitation side of the vehicle.

This situation persists irrespective of whether we are connected to 240V mains.

When I start the engine, I can hear a relay chattering but, thus far have not been able to locate the relay. However it appears to be in/under the dashboard.

I have visually checked all of the fuses on the Electroblok/Schaudt control box and all seem ok. The vehicle is a 2006 Dethleffs i7870 A class built on a Fiat Ducato base (2.8JTD). Due to the vehicle being an A Class, access to the engine Bay Area is limited/difficult. However, presumably there will be a few relays somewhere under there!

On a number of previous occasions when we've had the motorhome on our drive, we'd noticed that, occasionally the 12 V on the habitation side had 'tripped'. This was rectified simply by switching the 12V switch on the panel above the door off and on (a single time). Presumably, these previous instances and this latest one have the same root cause.

If anyone has a wiring diagram for a mid 2000s fiat/Dethleffs that they could send me, that would be fantastic.

Similarly, any suggestions on the likely culprit would be most welcome.

Thanks

Ian

 

[Camping Gaza]

Bit of a long shot but if you have "reset" it before using the switch on the panel, perhaps, just perhaps, the panel switch is US, the connectors loose or dirty or switch contacts dirty. If you can get to it remove panel and check the connections before ripping your dash apart?

 

[Pausim]

My Electroblok has a very small switch on it which turns off the 12v supply. If you have one of these I don't want to suggest that you haven't checked it but it might be another candidate for a malfunction. It appears to operate a relay within the Electroblok.

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[hilldweller]

You'll be able to download the diagram off the schaudt web site.

Good old French Hypermarche will provide the DVM.

Relay chattering ? Sounds about the right time for split charge relay near the engine battery, if fitted that is because the electrobloc my do this function.

 

[DavidG58]

we have had daft things like that with ours, switch off the electro bloc and also remove the main master fuse, remote from the other fuses, resets everything on ours, you might just get lucky, I have a couple of times and can be done without dismantling anything

 

[bigtwin]

Bit of a long shot but if you have "reset" it before using the switch on the panel, perhaps, just perhaps, the panel switch is US, the connectors loose or dirty or switch contacts dirty. If you can get to it remove panel and check the connections before ripping your dash apart?

Yes, I've just been behind the panel! The switch is part of a circuit board so not very removable! I've rattled the switch back and forth a few times just in case but with no joy.

I'm suspicious of the chattering relay (although it has now stopped chattering!). I may see if I can figure out the contacts on the switch and try bridging them to see if that makes a difference.

Ian

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[Lenny HB]

My Electroblok has a very small switch on it which turns off the 12v supply. If you have one of these I don't want to suggest that you haven't checked it but it might be another candidate for a malfunction. It appears to operate a relay within the Electroblok.

That switch has a reputation for failing well worth checking.

 

[bigtwin]

I

My Electroblok has a very small switch on it which turns off the 12v supply. If you have one of these I don't want to suggest that you haven't checked it but it might be another candidate for a malfunction. It appears to operate a relay within the Electroblok.

I've tried that with no joy but thanks for the suggestion.

Ian

 

[bigtwin]

You'll be able to download the diagram off the schaudt web site.

Good old French Hypermarche will provide the DVM.

Relay chattering ? Sounds about the right time for split charge relay near the engine battery, if fitted that is because the electrobloc my do this function.

I will try the download later.

Just my luck that the Hypermarche that we tried today didn't have one!

Does the split charge relay look just like a normal relay or is it different?

Ian

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[bigtwin]

That switch has a reputation for failing well worth checking.

That's a seat out job to access the Electroblok!

I'm keen to focus on the split charge relay as I suspect that it has isolated the habitation side. I just need to locate the damn thing!

Ian

 

[tonyidle]

The split charge relay shouldn't isolate the habitation battery - it simply disconnects the alternator / starter battery when the engine isn't running. It's built into the Electrobloc. A more likely possibility (if your vehicle has one) is the relay that turns off all habitation services when the engine is running. That one could easily cause the fault if it failed,.

 

[TerryL]

There was another thread on a similar thing a couple of days ago. Solution was to remove the control panel, disconnect it, wait about 30 secs then reconnect.

Might be worth a try.

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[hilldweller]

Does the split charge relay look just like a normal relay or is it different?
Ian

On our Burstner it's mounted right next to the battery rather crudely. On second thoughts though I'm not sure why it would chatter. What it does is just join the engine battery to the hab battery when the alternator is generating, so if the hab battery is knackered a lot of current might flow and that could destroy the relay. Would it chatter ? Not sure.

 

[hilldweller]

It's built into the Electrobloc. A more likely possibility (if your vehicle has one) is the relay that turns off all habitation services when the engine is running. That one could easily cause the fault if it failed,.

Our Electrobloc EBL99 switches an external split charge relay but in effect it's just the alternator D+ looping through the EBL. This same D+ line also switches an internal fridge relay.

I don't think German vans do the daft isolate the hab when driving thing.

 

[Lenny HB]

The split charge relay shouldn't isolate the habitation battery - it simply disconnects the alternator / starter battery when the engine isn't running. It's built into the Electrobloc. A more likely possibility (if your vehicle has one) is the relay that turns off all habitation services when the engine is running. That one could easily cause the fault if it failed,.

Habitation electrics are alway on in German vans turning them off is apeculiar thingg that only UK converts do, a hangover from caravans.

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[bigtwin]

Thanks to @Camping Gaza , @Pausim , @hilldweller , @DavidG58 , @Lenny HB , @tonyidle and @TerryL for the thoughts and suggestions regarding my loss of habitation 12V,

All sorted now - the usual trick of unplugging plugs/sockets (on the panel aboveboard the door) did the trick. More often than not, it's something simple like this - pretty much as @Camping Gaza suggested in the first response on the thread.

Thanks all until next time.

Cheers

Ian

 

[Camping Gaza]

Well done Ian, Happy trails!