Dometic fridge compressor not working

[Paul brooks]

Could someone advise please. My dometic fridge has an intermittent red flash indicating low power. I’ve charged the leisure battery 14.7 . Turned the fridge on and there’s an amber light I think means electric only and the red is still flashing every few seconds . The compressor doesn’t appear to be kicking in .

 

[DXX]

You don’t mention which model.
There have been multiple threads on much the same, in most cases it’s either a battery with good voltage but no load capacity or poor wiring leading to a significant voltage drop at the connection to the fridge. Either or a combination of wrong cable cross section, poor connection, excessive cable length and damaged leisure battery.
Have a search on the Forum.

https://www.dometic.com/assets/49/30/installation%20and%20operating%20manual_64930.pdf

 

[Pete C]

Which Dometic fridge is it ? Can you post some pictures.
Has it worked OK before ?

Pete

 

[Paul brooks]

Hi Pete
I’ll post some pics tomorrow thanks for your reply

 

[Paul brooks]

You don’t mention which model.
There have been multiple threads on much the same, in most cases it’s either a battery with good voltage but no load capacity or poor wiring leading to a significant voltage drop at the connection to the fridge. Either or a combination of wrong cable cross section, poor connection, excessive cable length and damaged leisure battery.
Have a search on the Forum.

https://www.dometic.com/assets/49/30/installation%20and%20operating%20manual_64930.pdf

Thanks for the info . It’s a CRX . For a while I could here the compressor trying to kick in , running for a short while then stopping, it did this all night before I realised the leisure battery didn’t have enough charge in it. I’m thinking I’ve damaged it ?

 

[DXX]

The fridge operates on a thermostat so it would stop and start anyway. Obviously the red light is indicating that all is not well, in most cases it isn’t the fridge.
I‘ve got a CRX50, I find that setting 2 is plenty cool enough.
If the leisure battery has been fully discharged for a while it maybe degraded, if you get load tested at a battery specialist they’ll be able to tell you.

 

[AussieMick]

As stated above 99% of posts on here about fridge problems turn out to be low voltage from a failing leisure battery .
Dometic fridges will cut out when the supply voltage to it falls below the voltage mentioned in the manual.
It is very important to keep your leisure battery charged.
I leave mine on an ehu when not using the van.
A failing battery can have a decent voltage reading after charging but when connected to a load, ie fridge, it will discharge quickly.

 

[Paul brooks]

Thanks for all the advice. I’ll get the battery checked over
Rgds Paul

 

[Pete C]

Best way to do this is to measure the battery voltage when the fridge is trying to run.
Let us know what the voltage is.

Pete

 

[Nigel W]

I seem to remember another thread about a similar problem which was fixed by disconnecting the fridge and then reconnecting - basically a reset.
worth a try?

 

[AussieMick]

I agree with @Pete C , charge your battery fully, take voltage then turn on fridge and take reading of voltage as compressor starts. You may find voltage dies quickly, eg 12.8 v no load, then down to 10 v or 11 v when load applied.
If battery is ok it would only drop from 12.8 v to 12.6 v, something small like that.
When my leisure battery was dying it would go from fully charged 12.9v to 10.5 v when fridge was on.

 

[DXX]

Not sure if I’m correct here so somebody please confirm or correct please.
On a Bluemotion van which never charges the vehicle battery over 80% if you don’t have solar or EHU connected and only have a B2B charger the leisure battery voltage will never be higher than the vehicle battery voltage.

 

[Sim60]

No - B2B will fully charge the leisure battery. If you have VSR , then leisure battery only charges to the starter battery level

Simon

 

[Paul brooks]

Best way to do this is to measure the battery voltage when the fridge is trying to run.
Let us know what the voltage is.

Pete

Hi Pete
The battery is showing 7.2 this morning it was at14.7 when I switched the solar off last night. Fridge and interior lights were all switched off. Looks like battery is defective I think. It’s only a year old so still in warranty. Does this make sense?
Rgds Paul

 

[Sim60]

You may find the battery vendor will argue that you’ve discharged the leisure battery to death rather than it being defective

 

[Paul brooks]

So just for future the battery must not be run too empty. This wasn’t explained to me when having the conversion But either way they can test it and hopefully that’s the fault. Thanks for all the help and if there’s anymore advice for future please pass it on to me
Rgds Paul

 

[AussieMick]

Unless you have a lifepo4 ( lithium) battery you shouldn't take it below 50 % of full charge (around 12v) often or you shorten its longevity.

 

[DXX]

Yes you shouldn’t run a leisure battery too low too many times.
While a year seems a short time I agree you probably won’t have a leg to stand on with warranty unless the manufacturer has a very generous policy on warranty.
I bought a leisure battery fully intending to fully discharge as it’s used for an electric outboard motor, I’ve probably had about 60 complete discharges before it died which I’m happy with.
Gone LiFePo now.

 

[Paul brooks]

That’s great thanks for the help and advise