Lunar CHamp H591 electrics

[Rover Prufski]

Unfortunately I didn't see the thread about Leaky Lunars before I purchased a Lunar CHamp H591...

Anyway, I've just purchased a 2004 Lunar Champ H591 motorhome, and have a few problems with the electrics Broken Link Removed
Does anyone have a copy of either a wiring diagram or the wiring scheme (i.e. where the wires run) for it please?

The fridge is not working, the toilet flush & indicator are not working, and the lighting circuits switched from the wall switches by the door and in the bedroom are not working. So I think it's the circuits on the 10A fuses which are faulty, even though they all have 12V at the fuses and the fuses are fine.

Everything was working perfectly, then I gave the motorhome a rather over enthusiastic wash on the outside around the top reversing light, which caused problems with the brakes lights, so water might have also leaked inside and got into the bedroom lights circuit, but I don't know where/how...

Also, I screwed on a little holder into the thin section of wall adjacent to the window by the hob.
I'm not sure if this hit any wires or not, as I don't know if any run down there...

Any ideas on what to do please?

Thanks
Helen

 

[autorouter]

I don't know much about that brand of motorhome, but here's a possibility. British motorhomes have a feature that all the habitation electrics are switched off whenever the engine is running. I presume it is done by a relay or a set of relays controlled by one master relay.

This controlling relay may be faulty, and may be failing to allow the habitation electrics to power up when the engine stops. It could be a bad connection to this relay. I don't know where it is on this motorhome, maybe other funsters have more of a clue than me.

 

[Rover Prufski]

Thanks for that idea, but unfortunately some of the 12V circuits are working, so I don't think it can be the answer

The Heater circuit, the water pump, the bathroom lights, the two spot lights in the lounge area and the two spot lights over the sink/hob are all working.

So it seems to be what is termed the Lower wiring loom and Upper wiring loom in the Calira Electric System manual, but I don't know what's on each or where the wires run... I'm not sure if the fridge indicator and ignition are part of these, or whether the fridge circuit has been affected too. The fridge gets a bit cold when plugged into the mains, but does not freeze in the freezer compartment.

I'm getting a low voltage at times on the light switches, anything from 1V to 4V, but not the 12V that should be there.

Any suggestions?

 

[autorouter]

First, I need to tell you I've never even seen a Calira unit, so this is all from the documentation. Anyone with hands-on experience will have more information.

What is the exact model of the Calira unit? Do you have the Operation Instructions document to go with it?

In the operating instructions for the EVS 38/20-DS/IU, there is something called the 'User Relay' that controls both the 10A User circuits. It is a 'Bistable Relay' (also called a latching relay). There is a particular pin (Pin 4 of the '12 Pole Flat Plug) that controls this relay. I guess all Calira units will have a similar design.

Do you have a multimeter? Check this pin to see if there is 12V on it.

 

[Rover Prufski]

Yes, the unit I've got is an EVO 38/20-DS/IU
The reference to the bistable user relay had me puzzled for a while until I realised they just mean the On/Off rocker switch on the control panel! (I'm guessing they've literally translated from the German).
As the light comes on and the rest of the panel works when this is On, I'm assuming that there's 12V present.

The Operating instructions show the socket of both the upper and lower wiring looms but don't say which cables go into which pin.

There's some info but tantalisingly too litte ...

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[autorouter]

"The outputs to the users only carry +12 volt if the bistable user relay has
switched on. The user relay only switches on if +12 volt control voltage is
applied to pin no. 4 of the 12-pole plug. The user circuits are each protected by
a 10 A fuse."

My understanding of this is, there is a bistable relay in the main unit, which switches the user circuits on and off. This relay is controlled by a rocker switch on the control panel, which goes to pin 4 of the flat 12-pin connector. The 12-way ribbon cable goes from the control panel to the main unit.

When you switch the rocker switch on and off, you should hear the click as the relay in the main unit switches. If not, is there any chance the ribbon cable could have been damaged by the screws for the holder you fitted?

 

[Rover Prufski]

Ah, okay. I'll try to check both ends if the ribbon cable. Thanks for shedding light on the terminology...

 

[Rover Prufski]

Yeah ha, I've found the problem - it's a lose connection on the ribbon cable somewhere. I moved it a bit to see if it fed downwards or upwards from the control panel and everything started to work again! So thanks for mentioning the ribbon cable Autorouter
I still need to find out where the lose connection is, but at least I know it's not due to the screw in the wall damaging the cable, as the cable goes up into the ceiling.