Thetford Fridge not operating on 12v when driving again!

[Jim Schush]

It was only 10 months ago that our Thetford fridge failed as we left the ferry at Newhaven. On this occasion the PCB board was diagnosed as the fault and was replaced.
Last week after returning from France the fridge again failed on 12v whilst driving.
In addition to the fridge fault the vehicles 12v battery meter fails to read the vehicle battery voltage however it does give a reading for the leisure battery’s.
When the vehicle is on ehu the fridge switches to 240v and the battery meter works fine.
I have just checked the PCB board and this looks fine with no bad fuses or scorched circuit board. I have checked all the fuses that I can find including the Schaudt fuses, battery fuses and a couple of fuses near the solar panel control and they all look fine and show clear readings on the multi meter. The vehicle is a 2018 Dethleffs Trend with a Schaudt Electroblock.
Any help or suggestions as to a possible fix would be greatly appreciated.

 

[Barchetta47]

I don’t know if this is an option for you but when our auto 3 way fridge stopped working on 12v we had an auto electrician just fit a separate circuit by passing the pcb and installed a separate switch which we turn on whilst travelling.

 

[GeoffnDee]

As you are also not getting a starter battery voltage reading ,It could be worth double checking any fuses near the starter battery positive terminal

 

[Landy Andy]

Are you sure the hab side is receiving the trigger from the van that the engine is running?

 

[Jev88]

Fuse and relay near engine battery. Might explain not seeing a battery voltage via onboard display.

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[DavidG58]

Our D+ / 14V relay activated by alternator output failed on ours

It also meant our E&P didn’t work , you might find something else isn’t working that should, maybe step alert if this is your problem

 

[Lizbiebrowne]

I don’t know if this is an option for you but when our auto 3 way fridge stopped working on 12v we had an auto electrician just fit a separate circuit by passing the pcb and installed a separate switch which we turn on whilst travelling.

I did similar on my Thetford N145 which had never worked on 12 V since I bought my van. The 12 V heating element can be powered directly from the starter battery (assuming the element is ok) and cools the fridge and freezer fine. I fitted a relay that switches off the fridge when the engine starts so there’s no danger of the 12 V element operating together with the gas or 240 V element.

L

Thread 'Fridge not working on 12V but element and fuse ok - time for creative thinking?'

May 18, 2024

Had a thought during the night!

My Thetford N145 fridge won't run on 12 V. There are three fuses on the Control Panel: two blade fuses, 5A and 30A, and a glass fuse. I've removed the blade fuses and replaced them - no change, fridge still doesn't work. I've not been able to remove the glass fuse (too tight and don't want to break it) but it looks good through the glass.

There are three cables feeding the fridge from Block 1 on my EBL100: a Blue and Brown cable from Pins 3 and 4 that carry 14.4V at all times and a smaller Yellow cable from Pin 1 that reads 14.4 V only when the...

• Lizbiebrowne
• Replies: 26
• Forum: Fridges & Ovens

 

[Jim Schush]

I did similar on my Thetford N145 which had never worked on 12 V since I bought my van. The 12 V heating element can be powered directly from the starter battery (assuming the element is ok) and cools the fridge and freezer fine. I fitted a relay that switches off the fridge when the engine starts so there’s no danger of the 12 V element operating together with the gas or 240 V element.

L

Thread 'Fridge not working on 12V but element and fuse ok - time for creative thinking?'

May 18, 2024

Had a thought during the night!

My Thetford N145 fridge won't run on 12 V. There are three fuses on the Control Panel: two blade fuses, 5A and 30A, and a glass fuse. I've removed the blade fuses and replaced them - no change, fridge still doesn't work. I've not been able to remove the glass fuse (too tight and don't want to break it) but it looks good through the glass.

There are three cables feeding the fridge from Block 1 on my EBL100: a Blue and Brown cable from Pins 3 and 4 that carry 14.4V at all times and a smaller Yellow cable from Pin 1 that reads 14.4 V only when the...

• Lizbiebrowne
• Replies: 26
• Forum: Fridges & Ovens

I have had my EBL repaired and have been advised that when running the fridge on 12v whilst driving the fridge is using 190w on the 12v element. This equates to about 15.8 amps which I am told is very close to the limits for the Lok n mate connectors. This would explain why I always seem to have fridge issues after long trips to Europe!
I have been informed that it’s possible to wire the fridge directly to a suitably fused power source without the EBL similar to how Lizbiebrowne as done .
Now I just need to work out if it’s a job that I can do or if I need to find a local auto electrician to do the job for me.

 

[Reallyretired]

Also could be that 12v element is burnt out. Test for open circuit and replace if necessary, it's not a difficult job, or wasn't when I had to do it years ago on a much older fridge.

 

[StillGoing]

I have had my EBL repaired and have been advised that when running the fridge on 12v whilst driving the fridge is using 190w on the 12v element. This equates to about 15.8 amps which I am told is very close to the limits for the Lok n mate connectors. This would explain why I always seem to have fridge issues after long trips to Europe!
I have been informed that it’s possible to wire the fridge directly to a suitably fused power source without the EBL similar to how Lizbiebrowne as done .
Now I just need to work out if it’s a job that I can do or if I need to find a local auto electrician to do the job for me.

Many Hymer and other makes of motorhomes are wired from the EBL without any problems.

It would be worth checking the state of the fridge plug into the EBL. Some people have experienced pins burning out.

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[Peavy]

Many Hymer and other makes of motorhomes are wired from the EBL without any problems.

It would be worth checking the state of the fridge plug into the EBL. Some people have experienced pins burning out.

I agree with this.
My Thetford is wired to the EBL protected under a 15A fuse, and the input current is, I believe 7A max.
15.8A is way too high? Maybe there's something wrong with the OP fridge?

 

[Jim Schush]

If I can just add some context to this issue. We purchased the van new in 2018 whilst still working and for nearly 3 years (relatively moderate usage) we had no issues at all.
After taking retirement in 2020 we started to use the van a lot more and since then we travel into Spain twice a year ( we use the van approx 190 days a year) and it’s since then the fridge has caused a few issues.
We have had it looked at by 1 main dealer and 3 times by local mobile techs. I myself have spent hours checking the external wiring and on 2 of the above problems I found the fault. Each time we have always found burnt out external connections, PCB board, Mate N Lok connectors and on this occasion the EBL itself.
The fridge fitted in our van is a Thetford N3142 and this is what the van came with when new. The spec sheet on the fridge shows energy use on 12v at 205w. I understand when using the fridge on 12v whilst driving it’s on one temperature and this temperature cannot be changed.
The fridge wiring to the EBL is approx 4 metres long.
Taking all the above into account I now think the fridge power consumption combined with the prolonged usage is simply putting too many watts of power through the Ebl and external connectors.
My thought now is to possibly wire the fridge directly to the vehicle battery via a suitable fused circuit and bypassing the EBL completely.
My question is how easy is this to do, any photos would be appreciated.