Hi all, Can anyone tell me why my 3 way fridge stopped working from the battery while driving? The fuse looks OK and the interior light is still on but the little triangle alarm symbol comes on as soon as I start the motor and the fridge starts to defrost. The fridge is a Dometic auto.
hi
Really need a wiring diagram to accurately check .
Is it a fused supply check fuse
While u are at the rear of fridge check also for power feed ""IN"
Any ways check for 12v at the element .
Check resistance of element
All else fails you have lost power across the switch
These are all generalizations may not be specific to your fridge .
If your fridge is a Dometic AES model (we can't check as you did not supply model number) you need three 12 V sources to run it on 12 V. One is a heavy supply to provide the power for the element. The other two are a permanent connection to the house battery to power the logic board in the fridge and a line from the vehicles ignition circuit to the "D" terminal. The latter one is to signal that the motor is running and signal the logic board to switch to 12 V operation.
You need to have 12 V power to each of these three positive terminals before the fridge will run on 12 V. The reason for that is so your fridge will not run on 12 V unless the alternator is supplying 12 V power to the fridge. If the fridge is running from the battery without that alternator assistance it will flog your battery to death. A starting battery will be discharged in 30 - 60 minutes. A deep cycle house battery will only last a few hours. Never attempt to run the fridge on 12 V without the motor running.
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PeterD Nissan Navara D23 diesel auto, Spaceland pop-top Retired radio and electronics technician. NSW Central Coast.
I am not a Gas Fitter/Technician I can only go by my own experience
Hope that I am not too late, or at least that your fridge is now working on 12 volts
Assuming that you do not have a multi meter to check the voltage at the fridge
I have come across the following 12 volt problems in a Dometic (older type fridge)
The blade fuse holder at the engine battery had partly melted inside, (it looked OK from the outside)
The melted plastic near one terminal was not allowing the fuse to make proper contact, I had to look inside the fuse holder to see why it was not working correctly
A new fuse holder fixed this problem
Behind the fridge you will find four wires going into the fridge
Two of those 12 volt wires (if the bodywork was made by Jayco), will be thin and the same colour, (mine were both white)
These thinner wires give a permanent 12 volt to the fridge, from the house/leisure battery/s (these are OK as the light inside the fridge is working)
The other two wires will be thicker and coloured red (for positive) and black (for negative)
These wires come from the engine battery (through a relay with the engine running), to the 12 volt element of the fridge
You can check that the wires are not loose at the connections, and at the 12 volt element
If you are near someone with a multi meter, they can check at the 12 volt element
Firstly if there is power at the element, with the engine switched on
Secondly if the element is OK
If you can let us all know how you got on, and what the problem was, when the fridge is once again working on 12 vols, it may help others in the future
Thank you for taking the time to explain that. You're right that I don't have a test kit or even know how to use one. At the moment thought, the fridge seems to have fixed itself, which would suggest a loose connection. I'm on 240 now but will take it to be looked at when I get the chance.
