We have recently bought the van listed. This is our first foray into caravanning after camping.
We have just had our first trip to a fully serviced site.
All works fine ( a few bits took some working out but it just added to the experience)...
The van is now outside the house to fix a few bits and gives our son or I a place to chill.
Here's my question (finally I hear you say)
All the electric works fine when on ehu. Both the 240 and 12.
When I disconnected the ehu I seemed to have no 12v...
I checked fuses, chased cables etc. All was OK. Checked battery and had 12.6v so deemed battery OK.
Got under seat behind battery and checked fuses and relay etc then was able to tack onto a 12v socket. This gave only .5v when main switch was on caravan, 0v on middle or car. This worked as this flawlessly.
I was at a loss but now found a way to get my caravan to switch to 12v mode.
I was lost as sometimes if I just waited the 12v might come on but if i have the ehu on, switch on charger, switch to caravan, turn off charger, knock off main fuse... I have 12v
If I turn caravan to centre and back I lose 12v
I would like to travel and use the leisure battery.. Anybody any ideas? What is going on. Am I missing something.
Sounds like you've got a bad connection between the battery and the rest of the system. Sometimes bad connections show voltage but when you try and draw current the connection fails.
Try plugging something in the 12v side and go round wiggling all the connections
Hi, the caravan 12v selector switch needs to be set to caravan when using the caravan on hook up or not. With the switch in centre position 12v is off and in the 3rd position car 12v is selected if connected to the car.
I think he's aware of the switch position from his comment:
"... only .5v when main switch was on caravan, 0v on middle or car."
One thing the Op hasn't mentioned though, is what van this, other than ".. the van listed". It would be useful to have all detail.
You may have a van that provides 12v from a transformer while charging the battery separately from a charger (hence loss of 12v when off EHU).
I'd agree with the suggestion of a poor connection from the battery side and that circuit needs a good examination. Have you measured the battery voltage while being charged too?
Sounds to me like a relay problem. When the charger is switched on it energises the relay giving you 12 volts. The relay stays energised as long as the switch is left to "caravan", but drops out when you switch to "off" (centre) or "car". Result, no 12 volt supply when you switch back to "caravan" without the charger being on.
I would get your 12 volt system working as you describe, then listen for a relay dropping out when you switch the battery selector switch to "off".
you could have a dead battery.. if they are left flat for too long they will not take any charge ever again..
when on the mains the charger will provide 12 volt power the battery isnt doing anything.. when off the mains the 12 volts has to come from the battery.. if its dead you wont have any 12 volt power at all..
i think you have a dead battery.. the symptoms fit..
If it a modern caravan, probably post 1998 ish there is a habitation relay fitted which disconnects all 12v in the caravan when towing. This may be faulty.
to be honest the first thing to do should be test the vans battery.. take it off the van charge it separately and make sure its putting out power.. if it isnt all the other possibilities are just wasting time..
when left flat for too long a lead acid battery will be more like a house brick than a battery.. totally dead..
I can see what you are saying trog, and you are right about a battery being ruined if it is left discharged for a long time, but I don't think it's the battery in this case.
Stevieag said that the 12 volt works ok off the battery, even after the charger is switched off, as long as he doesn't switch off the battery selector switch. That seems to suggest that the battery is fine. It sounds to me like a relay is dropping out when the battery selector switch is turned off, isolating the battery.
Tested a few times today and all seems to work ?..... Said it was weird 12v. I can hear nothing happening at the relay in the front of van,behind battery where car electrics come in.
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Topic: weird 12v electrics
