Unusual Thetford fridge issue

[Winstanley]

First post so please be gentle !!

But if you like a challenge read on.

I have a new to me, 12 months ago, Autotrail Tracker fixed bed on a 2013 Fiat Ducato.

It has fitted a Thetford N3175 AES three way fridge which works fine on mains and gas. However it does not work on 12 volt. Fridge / Freezer chilled down on mains to roughly + 2 fridge and - 15 freezer. After travelling for more than an hour the fridge is +8 or more, freezer is around zero. This is the same on every journey.

It has been back to the dealer about six times and so far has had every electrical component on the fridge replaced including two new 12 volt elements. The EM40 unit has been replaced together with the wiring from it directly to the fridge. Vehicle alternator, battery and leisure battery checked and all fine.

On the last visit to the dealer they changed the 12 volt element again, chilled it on mains then ran on tick over for two hours and temperature steady at -12 and + 3. Vehicle driven for an hour or so and fridge / freezer heats back up again.

My dealer, who I cannot fault and who have gone well above and beyond what I would expect have sought technical advice from Thetford and Autotrail neither of whom seem to have a solution.

Any thoughts would be greatly appreciated.

 

[thenomad]

Not true for vans I've had for the last 15 years, they all worked fully on 12v using their thermostat.

Why don't you just call the fridge manufacturers technical department and ask them.

 

[GeoffnDee]

I think you may find that the earlier Thetford N175 (pre 2012) had thermostat control for gas and 240v but not 12v and the later Thetford N3175 has thermostat control on all sources.

 

[VXman]

I was told by a caravan mechanic that the 12 volts supply from the engine is only meant to maintain the cold temperature not to actually call it down so you may be struggling unless you put a larger element in

I'd suggest this is the kind of b*** s*** designed to fob a customer off.

The point is modern fridges do have decent elements in them. That is why I gave the example of mine - 205 watt 12volt element isn't much less than the mains element. Therefore the 12 volt performs pretty much the same as when on mains.

 

[Spanner]

Has anyone measured the current draw (amperage) at the 12 volt supply connector to the element ? Should be drawing approximately 15 amps when the engines running