Hi we have a problem with our fridge whilst towing. When switching to battery as it's a three way it just doesn't work. We have checked all the obvious things like connections etc but just wondered if any one could offer advice as we are off to france soon. Thanks
Not sure whether you have the older 2 x 7pin socket setup with the 12S (Suplimentary) wiring in the second socket or the newer 13 pin single socket but here are the wiring details for both. Remember the fridge power usually comes on ONLY when the car's engine is running a bit more than tickover so that the alternator is powering it and its not draining the car's battery.
Are you sure it dosen't work? If you just tow it with an empty fridge & then put your hand inside it won't really feel cold. The way to tell is to tow for half hour then put your hand on pipes in ice making compartment, pipes should feel distinctly cold.
If it don't work at all & power is definitely getting to fridge then it is probably 12v element failed, they can be replaced but fridge will have to come out.
As mentioned above, the fridge will only operate on 12 volts when the car engine is running at relatively high revolutions.
If you are checking when the car is idling there will be no current going to the fridge.
Daves1
I understood that if you selected CAR on the 3-way switch, that meant you were drawing power from the Car Battery and not from the Car Alternator.
On the 12S socket, the power from the Car Alternator, when the car engine is running and producing sufficient power, will charge the Caravan Battery and the Fridge.
Just a small point philz55.
The three way switch you mention will have no effect whilst you are towing. When the car engine is running all 12 volt power in the caravan is automatically switched of.
The "CAR" position on the switch is there should you wish to use the car battery instead of an onboard battery only whilst you are stationary, connected electrically to the car and with the ignition off.
It is not usually recommended because you may drain your car battery.
Daves1
most modern cars wired for caravans have second relay fitted so fridge will only receive 12 volt from car when engine running and prevent car battery reduced voltage for ECU management
There is no three-way switch in the Ranger 550/6, the panel's have a simple 12v on/off with auto habitation relay. I think also, that this Ranger had a standard Thetford N97 fridge without any indicators/lamps.
As has been said, the fridge will only operate while the car engine is running at a suitable speed, however the fridge isn't hugely efficient if trying to chill when connected to the car (especially if the ambient temperature is a bit warm already).
It could simply be (as has also been said) that the fridge isn't being given chance to chill, or worse case scenario a fault with the product or the wiring.
Difficult to assess if you don't have a meter of some sort to measure for voltages being present.
Hi , thanks for the advice by all. It was really useful. We have given the fridge plenty of time to chill ie it should be no problem as we are pitched seasonally so the fridge is always on, we set off to to dover last year and arrived in france with no cold evident but once pitched on site via Ehu it worked fine. My father has checked the inner electrical components with a test meter. I think as suggested it may be the tow bar wiring. I just wondered if there is any way of telling if it's definitely that? It is three way as described in the instruction leaflet we had when purchased. It's model number RM4270 which is made by dometic
You need to check the cars wiring. Firstly ensure that you have full wiring including the charge relay, sometimes called a smart relay. If you have one fitted, then you need to check power output from the relevant pin on the socket of your car, generally PIN number 6 red cable on 12s sockets.
As mentioned the car needs to have been running fir a couple of minutes and at around 2000rpm for the relay to click in.
If you can locate the relay, sometimes you can hear a click to signal it is active, some have a indicator light to signify this too.
My smart relay has an adjuster for the sensitivity at which it clicks on, this could be adjusted if you have one.
If you or someone has access to a multimeter you should be able to check the above.
Hope you get sorted.