Fridge not working from battery
- Thread starter Johnnny
- Start date
Assuming 3 way fridge it will work on 12v only when the engine is running.
Like he said - fridges don't normally work on 12v alone unless engine is running. If it's 3 way you have 12v whilst driving, gas or electric while parked up and hooked up, gas only if no EHU.
Fridge make/model would be useful. A fridge using the leisure battery to cool will discharge it to the point of damage within a day. 12v from the leisure battery is used only for control of the fridge functions.
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Yebbut, even though the red light is showing did the fridge actually cool on 12v when driving?
The fridge's 12v heater element (which probably* has its own power supply and fuse separate from the 'red light') may have died.
* As previously requested, the fridge make and model would enable more certainty.
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i bet its Dometic.
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I'll have half a crown each way
Lenny HB
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Every van we have had when stationary if you switch the fridge to 12v it runs off the hab battery. There is a relay in the Elektroblock that switches the fridge between the starter battery & hab battery triggered by the D+. Fairly standard on German vans.
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Sapper520
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My fridge works when the engine isn’t running…..Compressor fridge run off my leisure batteries. 
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Good for you, but until we're told the OP 's fridge details we may as well carry on guessing or spend our time waving our willies out of the window.My fridge works when the engine isn’t running…..Compressor fridge run off my leisure batteries.
Johnnny
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Sorry I'm at work away from van but it's
Electrolux RM4230
What I'm trying to describe is before yesterday if I pressed green light it always lit up from liesure battery
Now only lights up when on ehu or mains from house
Thanks
Electrolux RM4230
What I'm trying to describe is before yesterday if I pressed green light it always lit up from liesure battery
Now only lights up when on ehu or mains from house
Thanks
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No prob. Someone has to pay my pension
You have a 3 - way absorption type fridge which draws a lot of current when running at 12v. (maybe 7 to 10amps) and would quickly flatten the leisure battery without the engine running, (possibly within around 3 hours) depending upon how much leisure battery capacity you have or whether you have solar panels. (Are you quite sure it used to work o.k. on 12v without the engine running?).
The manual says:
As you will see, the fridge cooling system has two heaters, a 240v and a 12v.
You haven't answered whether (although you said the 'red light' illuminates) it does actually cool on 12v with the engine running. If it doesn't it may be that the 12v element is duff.
You have a 3 - way absorption type fridge which draws a lot of current when running at 12v. (maybe 7 to 10amps) and would quickly flatten the leisure battery without the engine running, (possibly within around 3 hours) depending upon how much leisure battery capacity you have or whether you have solar panels. (Are you quite sure it used to work o.k. on 12v without the engine running?).
The manual says:
As you will see, the fridge cooling system has two heaters, a 240v and a 12v.
You haven't answered whether (although you said the 'red light' illuminates) it does actually cool on 12v with the engine running. If it doesn't it may be that the 12v element is duff.
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Johnnny
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Yes does cool when engine running and red light on
Without getting too much into it just wondering why green light used to light from liesure battery and now only from ehu.what could have changed?
Without getting too much into it just wondering why green light used to light from liesure battery and now only from ehu.what could have changed?
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If it normally works from the leisure battery when the engine is not running, then there will be a 'High Current' supply from the leisure battery. It is probably totally separate from the Low Current supply to the fridge control board. There will be a separate fuse, probably 15A or 20A, maybe near the leisure battery, that is worth checking.
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I have an almost identical fridge (model and age) and the green light only illuminates when on EHU.
My fridge automatically stops running on 12v when the engine is turned off but that is how it has been connected (set up externally) and has no bearing on the fridge circuitry or connections..
Could your memory be playing tricks? Your green switch would have always been for EHU only and the red one for 12v operation but in my case only when the engine was running. As said, if the red switch powers the fridge on 12v without the engine running (and dependant upon your battery capacity) it wouldn't have run for long unless you have sufficient solar power as well.
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Not sure thats the case with modern vans. Our 2021 Burstner doesn't. They are generally set up NOT to run off 12V when the engine is not running. If you manually select 12V on ours when the engine is not running the red error light will flash.
Johnnny
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Have opened a can of worms here yes Have checked 15a fuse for fridge and my memory not playing tricks lol but did definitely light up green light from liesure battery only although could see charge drop quiet quickly from voltage display i Have plugged in.must be the way my van wired up when I bought it nearly 4 years ago and definitely lit up green until yesterday from liesure battery
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For several reasons I can't get my head around how the circuitry would work if the 12v supply (alternator &, leisure battery) and the 240v EHU are/were both switched and fed to both of the heater elements at the same time through the same green switch (as well as 12v by the red switch).
My brain's getting a bit scrambled now so I'll go and lie down in a cool darkened room for a while and maybe I'll work it out. Subscribers do not see these advertisements
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For several reasons I can't get my head around how the circuitry would work if the 12v supply (alternator &, leisure battery) and the 240v EHU are/were both switched and fed to both of the heater elements at the same time through the same green switch (as well as 12v by the red switch).
The way mine works is....
12 Volt: The hab battery supplies 12V for the electronics side the the fridge (dispaly panel, internal light etc.) The 12v heater element only operates with the engine running and supplies a D+ signal to facilitate this switching. That power comes from the engine battery/Alternator.
240 Volt: When EHU is plugged in 240V takes over.
Gas: When the engine stops and you are not on EHU there will be a 15 minute period where there is no 12V and no gas (safety mode for when in fuel station). Then if the gas is on it will ignite the gas burner.
*This is all when auto mode is on. You can override auto but it will still not allow 12V operation at all.
Are you sure it's the fuse from the leisure battery supply? There is also the more usual fuse from the alternator/starter battery.
One possible way to run a fridge from the leisure battery would be to have a small inverter (150 to 300W) and send power to the 240V element from that. Then the green light would be on, and the power would be coming from the leisure battery.
Obviously there's several drawbacks to this method, but it's possible.
Sapper520
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Good for you, but until we're told the OP 's fridge details we may as well carry on guessing or spend our time waving our willies out of the window.
I’m too inadequate for it to wave anywhere.
Johnnny
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No worries but definitely fridge fuse 15a on control panel next to liesure battery
No inverter and yes ran battery down quickly
Must be the way wired up
No inverter and yes ran battery down quickly
Must be the way wired up
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Yes, thanks, I'm fully aware of all of that but the OP says that the green switch (which is specified by the manufacturer as the 240v switch) lights up when on EHU but until yesterday it used to light up when on the leisure battery.............surely the 'green switch' can't/could never? have switched on both the 240v and 12v heater elements at the same time or 240v would be fed to the 12v element and vice-versa. I can only guess at the possibility that that it's just the switch lighting up but not both the elements
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Lenny HB
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Had 3 Hymer's, 2008, 2014 & 2017 all capable of running off the hab battery. The only difference was the 2008 would auto switch to the hab battery if no other source of power, the others only if you select 12v manually.
If it's not set up to run off the hab battery you can't make use of the S+ connection to run off solar, which is very useful.
The 240V and 12V elements are entirely electrically separate, they can be removed and replaced separately for example. So it is quite possible to have both elements on at the same time. Bad idea, but possible in theory. The cooling circuit requires a definite amount of heat for it to work efficiently, about 100W or 200W usually. Too little or too much and it doesn't work. Two elements at the same time will stop the coolant circuit working.
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Yes I realise that, except that from earlier posts (it's all getting a bit confusing now) it seems that the wiring of both elements (12v d.c. and 240v a.c.) combine at and are switched by (only) the same green switch (engine off) since the OP said that until yesterday the EHU and the leisure battery illuminated the same green switch and it ran on 12v (engine off) if the EHU wasn't available. I know that some fridges have the sophistication to choose which power source to connect/use but the OP's RM 4230 doesn't.
On my same fridge the green switch switches only the EHU supply and the separate red switch connects the 12v from D+ via a 'normally open' relay but only when the engine's running, therefore my fridge doesn't/can't run on the leisure battery when the engine is off.
Maybe the OP's wiring has been modified from standard but the fridge wouldn't run for very long on just the leisure battery without solar power.
I think I may need to lie down again and perhaps untwist my knickers.........
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Well, personally I'd like that option as I have plenty of battery power and solar. It would be good to be able to use some of that 12V power instead of gas - on occasions. I did do it recently when we had problems with the gas - but that used an inverter to an ehu cable going out the window and back into the van!
What is this S+ function? On the solar controller or on the EBL?
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