Elddis Avante 2006

[Billybushwick]

Hi all, I am at my wits end after trying to fit a leisure battery (110ah) everything was working before I hooked it up. The mains power was off (I unplugged from the mains) then opened the battery door and pulled out the positive and negative wires (no inline fuse) connected the positive first followed by the negative. Went into the caravan and checked that the 12 volt master was on 12v. I am not sure of any of the 12V stuff should work from the battery, but anyway nothing did work. I then plugged the mains back in and switched over to master, there was a clicking noise coming from the power supply, as though a relay was opening and closing but I could not find a relay. Trying out the 240V I got the TV - 2 lights working and that was it; no fridge, no spark from the ignition for the gas hob, just 240V only. I disconnected the battery and checked the fuse box under the seat, a 15a car/batt fuse had blown. So I replaced the fuse with a good one and tried again, still nothing, no 12V. I have looked for an inline fuse on the 12V under the caravan but I cannot find one anywhere. Deciding that it might be the power supply I bought a new 20a 240v from Ebay and hooked it up, still nothing, no 12V at all.
Does the power supply need a signal in order to get the 12v working? As I plugged in the supply and using my meter checked for a 12V current from the output side, I got no reading at all. Other than this I am stumped as my electrical knowledge is only basic, if anyone else has suffered such a problem I would love to hear any solutions as it is on my driveway at the moment and cannot be moved.

 

[Deejuk]

I assume you checked the battery is good, fully charged etc. Not knowing your model of caravan I'm not sure but if the battery is good, then perhaps start checking the wiring from the battery to the main box something could have come loose.

Hope you get it sorted

 

[ProfJohnL]

The mains power was off (I unplugged from the mains) then opened the battery door and pulled out the positive and negative wires (no inline fuse) connected the positive first followed by the negative.

Often an in line fuse is connected in the battery positive lead but its inside the caravan behind the battery box. It only takes an accidental touch of the wrong wiring on a battery to cause this fuse to blow. It's doing its job and protecting the wires from a battery short circuit current. I don't know why they don't design it into the normal 12V fuse box to make it obvious and accessible.

. I am not sure of any of the 12V stuff should work from the battery, but anyway nothing did work. I then plugged the mains back in and switched over to master, there was a clicking noise coming from the power supply, as though a relay was opening and closing but I could not find a relay.

The purpose of having a 12V battery is so that the majority of 12V items, like 12V lights, and water pump can be used when mains power is not available such as caravanning off grid. With modern caravans the fridge also needs 12V power to run its control system, but it will only cool using 12V when coupled to a tow vehicle when its alternator is producing enough power. That is controlled by the caravans "habitation relay" This relay is designed to prevent habitation equipment such as lights and pumps from operating when the caravan is being towed, but a other terminals send power to the 12V element on the fridge, and to the caravans battery to top it up whilst traveling.

Interestingly, the symptoms you have described actually seem to suggest the Habitation relay may be activating and preventing the majority of 12V items from working. But as to why the relay might have operated is not clear:

Did you have your tow vehicle connected to the caravan with its engine running when you were trying the 12V items? If so disconnect to caravans towing plug, and try again.

Trying out the 240V I got the TV - 2 lights working and that was it; no fridge, no spark from the ignition for the gas hob, just 240V only.

Caravans often have a mix of 230Vac and 12V dc lighting , if only two lights came on when the mains was connected I'd suspect they were the 230V light fittings.

I have looked for an inline fuse on the 12V under the caravan but I cannot find one anywhere. Deciding that it might be the power supply I bought a new 20a 240v from Ebay and hooked it up, still nothing, no 12V at all.

How did you hook this up? specifically where did you connect to feed the caravan. If it was to the cars feed to the caravan, it would activate the habitation relay which would result in the symptoms you have.

Does the power supply need a signal in order to get the 12v working?

The 230Vac powered battery charger/power supply produce 12V (Actually nearer 13.8V) without a battery in circuit.

As I plugged in the supply and using my meter checked for a 12V current from the output side,
I got no reading at all.

Without knowing exactly how and where you connected the meter and the status of caravans electrical switches, this information has no value. Also you should not have been using a Current meter, you should have been using a voltage meter to detect the presence and value of any voltage.

 

[Billybushwick]

No, I've never hooked up the caravan whilst engine is running, not on the grey plug, it is dirty and has been wrapped up and tucked away under the towing frame, which is why I wanted to get the 12v fridge working whilst driving.
I meant voltage; I connected the meter to read 12V from the output wires (2 reds 2 blacks into one plug) there is just two spades inside the plug. I placed the positive onto the positive spade and negative to the neg. With the power unit connected to the 240V cable that comes in from the consumer unit I hoped that the output value would read around 13.5/8V but I got nothing. This is why I was wondering as to whether the power supply is shot. There is no inline fuse from the battery positive or negative, just a black cable that comes in from the battery box and into the fuse box. All fuses tested OK.
The habitation relay, is there a standard place where it might be located or is it part of something like a power supply? The old supply was clicking on and off, and when I opened the box to see if an internal fuse had blown I noticed several resistors burnt out, one was literally hanging from it's track.
**** I hooked up the caravan like on a site, only a 13amp plug to the 240V blue plug adapter and ran it from my house outlet******