I have a 2014 Triton and seem to have a problem with the fridge when the van is connected to the car during transit. There is little or no evidence the fridge is working, it is fine when connected to mains or gas, has anyone else experienced this or are my expectations too high. I believe the the socket/plug connection between the car and van is okay but am having it checked out, everything else works fine when connected to the car. Feedback would be very welcome, thanks in advance.

When a fridge is set to 12V and the van is connected to the car with the engine running above about 1000rpm then the fridge chilling will be provided by a 12V element powered by current from the car's alternator. If the car's socket wiring isn't set up for fridge connection it won't be powered. If the engine isn't running it won't be powered, if the engine is below 1000rpm it won't be powered and on a modern car the alternator gives priority to recharging the car battery after starting and the power to a caravan may be substantially diminished until the car battery is replenished. Added to that there may, of course be circuit problems in the van, including a failed 12V element. If your fridge has an interior light then both it and the fridge controls will be powered by 12V from the caravan battery whichever form of energy is utilised to power refrigeration. If you have the earlier fridge with no internal light then the power source lit switches are powered by whichever power source is refrigerating and therefore a lit 12V switch indicates that 12V power is reaching the fridge.

Many thanks, Steamdrivenandy a very detailed reply. Nothing is happening when in transit so engine always above 1000rpm then. The interior light is working so assume 12v is getting through to the fridge? As a matter of interest, there is a separate switch the turns on/off the 12v supply to lights wc flush etc, in the caravan, does that also supply the fridge? It is looking like it could be the heater element in the fridge being U/S even the though it was recently sercviced at Tebay (but that is another story).
How easy is it to get out the fridge out from its housing? Is the gas connection to the fridge a flexible or solid connection? Many thanks again.

On a separate issue, if anyone needs to change/repair the WC rinse pump there is a superb uTube video detailing how this is easily done.

I know I might be stating the obvious and you may know this already, but I wasnt familiar with this at first

When on 12V the fridge is only working on a trickle cooling effect: its nowhere near as effective at cooling as mains or gas power.

This means it doesnt cool down products in the fridge if theyre not cool already. The battery feed is meant only to keep already cooled content from warming up :)

Just a thought

I presume nobody travels in the van so it's impossible to say that 'nothing is happening' in transit. A caravan fridge is always best chilled down using 240V before a trip as for the reasons I detailed earlier the 12V element may not get enough power to bring the fridge interior down to what you'd expect, especially in 30C temps of recent days when the absorption type fridges don't perform well anyway.

I also carefully made the point that the light/controls 12V is from a completely different source and circuit to the 12V that powers the 12V refrigeration element. So having the interior light working does NOT indicate that 12V power is reaching the element. The interior light and control power comes from the van battery but the element power comes from the car's alternator.
Now that the heatwave appears over is a better time to judge fridge performance and checking whether your car is actually equipped to send 12V to a fridge is the first step, some brands do not wire in fridge or battery charging links unless specifically requested. If you establish power is coming in on the relevant pins then connections and fuses on the circuit need checking before assuming elements have failed.

On mine, the 12v switch is illuminated when the car ignition is on, with or without the engine running. It is my last check before departure.

Im not 100% sure, but if the fridges work like portable 12V cooling boxes then the 12V element in the fridge is a Peltier device.

Peltier elements are heat "pumps" which transfer heat from one side of the device to the other, depending on the direction of the electrical current

It depends what fridge you have.

If it's the older type with red and green lit switches then those switches receive power from either the EHU or car alternator as appropriate and that also indicates that the relevant power is reaching the fridge.

The car ignition has nothing to do with whether 12V power reaches the fridge. The circuit has a split charge relay that when it senses sufficient power coming from the car's alternator switches on the circuit to the fridge. That's why, when you switch the fridge to 12V without the engine running the bulb in the switch doesn't light, but when you start the engine, after a few seconds delay the bulb will light.

On newer fridges the controls are powered by 12V from the van battery and if you don't want to flatten the battery you have to turn the fridge off when storing the van. On such fridges the controls and interior light are always on when the fridge is switched on, even if the fridge is running on gas. However in those fridges the 12V control/interior light circuit from the caravan battery is totally separate from the 12V refrigeration circuit from the car's alternator.

In both cases the separation/lack of van battery involvement is done on purpose because the current draw to power the refrigeration on 12V from the caravan battery would flatten it in minutes.

Andy see post #6

All I can say is that shouldn't happen S&D as there should be no current flowing until the split charge relay opens when it senses current from the car's alternator.

If your fridge is being powered from your van battery it will make no difference whether the car ignition is on or off.

If it is powered from your car battery (which would be how power would show up when the ignition was turned on) then the car has been wired incorrectly and the car battery will take a caning and there's a risk that it might be flattened by the van fridge.

2005 Puck 120 original Dometic. RM 42** sorry it says Electrolux. Another correction, manual says Electrolux, Fridge has 'Dometic' on the front.

Maybe someone thought it was a good idea to have the car's 12V battery power available to run the fridge when there was no EHU, but as said that will quickly flatten the car battery and mean you can't start it. In a non EHU situation it's much more sensible to use gas rather than leave the van connected to the car with its ignition on just to power the fridge with the risk of not being able to restart the car.

Quote: eribaMotters wrote in post #13

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Andy, beware. My Skoda Yeti would feed the caravan fridge whilst the ignition was on but engine NOT running.

Colin

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