Electrical 12v fridge issue

Seano

New Member
Jun 12, 2021
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Hi all. I have a new model Jayco with a 3 way Thetford fridge which refuses to run on my new vehicles auxiliary battery (allrounder 105). The van fridge works ok when connected to my other vehicle which has single car battery. I get error code 6 which I indicates not enough voltage? My new vehicle has a dual battery system with a dc-dc red arc charger for the aux. battery which is then connected to the caravan's fridge. There seems to be a supply issue somewhere, can anyone help?
 
Last edited:

mikerezny

Well-Known Member
Sep 11, 2016
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Mount Waverley, VIC
Hi,
You will need a multimeter to do some investigating.

These fridges draw at least 15A and the most common reason they don't perform or give low voltage error is the use of inadequate wiring. In your case it will most probably be between the aux battery and the fridge. Since it works ok on another vehicle, you can make the first assumption that the problem is somewhere between the aux battery and the car socket.
You have not stated the model number of the fridge so it is not possible to be more specific.
First measure the voltage across the terminals of the aux battery.
Now you will need two people:
Whilst measuring the battery voltage get someone to manually switch the fridge to 12V and back. Is there any difference in the battery voltage?
Next repeat whilst measuring the voltage across the 12V heater terminals (the thick wires).
Next repeat whilst measuring across the fridge supply terminals on the 12-pin van plug or Anderson plug.
Post the results.

take care
Mike
 

Boots in Action

Well-Known Member
Mar 13, 2017
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Ferny Grove, Queensland
Hi all. I have a new model Jayco with a 3 way Thetford fridge which refuses to run on my new vehicles auxiliary battery (allrounder 105). The van fridge works ok when connected to my other vehicle which has single car battery. I get error code 6 which I indicates not enough voltage? My new vehicle has a dual battery system with a dc-dc red arc charger for the aux. battery which is then connected to the caravan's fridge. There seems to be a supply issue somewhere, can anyone help?
Hi @Seano, your symptoms definitely point to low voltage at the 3 way fridge input. As you say you have a dc to dc charger between your main cranking battery/alternator and your aux battery in tug, one might check to see what voltage is output from dc to dc charger and input into aux battery. I believe they are adjustable. Voltage to aux battery should be at the higher end of recommended range for allrounder 105 battery to cope with voltage losses between aux battery in tug and 3 way fridge terminals in van. 3 way fridge input needs to be between 12.5 volts and 14.0 volts for efficient operation. As @mikerezny said, use multimeter to check voltages and also if wiring from tug to van (including connections) is heavy enough.
 

Drover

Well-Known Member
Nov 7, 2013
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QLD
Even with a DC-DC charger you need the engine running to power up the van fridge as it will suck the goodness out of a fully charged battery quickly,and one that is slightly down won't last long especially on start up, try it with engine running then if no go follow Mikes test regime........................ What leds are showing on the redarc ??

It may also have a fridge switch fitted on the tug side ....
 

Seano

New Member
Jun 12, 2021
2
3
3
2478
Hi,
You will need a multimeter to do some investigating.

These fridges draw at least 15A and the most common reason they don't perform or give low voltage error is the use of inadequate wiring. In your case it will most probably be between the aux battery and the fridge. Since it works ok on another vehicle, you can make the first assumption that the problem is somewhere between the aux battery and the car socket.
You have not stated the model number of the fridge so it is not possible to be more specific.
First measure the voltage across the terminals of the aux battery.
Now you will need two people:
Whilst measuring the battery voltage get someone to manually switch the fridge to 12V and back. Is there any difference in the battery voltage?
Next repeat whilst measuring the voltage across the 12V heater terminals (the thick wires).
Next repeat whilst measuring across the fridge supply terminals on the 12-pin van plug or Anderson plug.
Post the results.

take care
Mike
Bingo, thanks Mike, required 6mm wiring, I had 4mm!.
Appreciate your assistance,

Sean