Dometic CRX - line voltage issue?

[bethamari]

Hi all,

Hope everyone is well!

We are away in Europe and have realised our Dometic CRX has stopped working properly.

The lights are on but we can’t hear the compressor anymore. There is a red flashing line and looking at the manual this only flashes once and then there is the 4 second gap. This comes up as a line voltage issue and possibly that the supply voltage is out of range.

We were on EHU. I tried turning it off by the power button inside the fridge itself and then removing the EHU cable so that it would be running off the leisure battery and turning it back on but it’s still doing the same. Leisure battery is relatively new lithium and having no other issues with it so far.

Any ideas on possible fixes we can do to resolve please? Did try a search but couldn’t see this exact issue elsewhere. Thanks

 

[Bigsidavies]

Mine sometimes throws a wobbler and it needs completely disconnecting from the power supply for a few minutes.
Worth giving that a try.
You’ll need to remove the fuse for the fridge if you can find it instead of turning the fridge off with the power button.

 

[bethamari]

Ace cheers! Driving to our next stop but will try that soon. I was thinking of trying turning off the Sargeant power box to see if that helps.

Would the fuse for the fridge be within that power box area or on the fridge itself? Thank you

 

[roadtripper]

Second the suggestions from @Bigsidavies

All 12v compressor fridges are sensitive to voltage issues, as the compressor motor starts it's essentially a short circuit and will briefly draw a very high current before it starts moving. When connected to a battery only this can cause a voltage drop and if sufficiently large it will fail to start, especially if the cable runs is under sized or the battery low.

After a couple of failed starts the controller will lock out and not start again for safety (keeping trying to start may overheating wiring if the motor is actually jammed) and to remove the lockout you need to fully remove the fridge from power - most of the apparent on off buttons on the fridge itself just tell the controller not to run, they don't actually disconnect the power.

 

[roadtripper]

Ace cheers! Driving to our next stop but will try that soon. I was thinking of trying turning off the Sargeant power box to see if that helps.

Would the fuse for the fridge be within that power box area or on the fridge itself? Thank you

The fuse is most likely inline as compressor fridges are generally wired as direct as possible to the leisure battery.

If you have one of the all in power units like a Sargent don't get confused by any mains breakers marked as a fridge - these systems are designed for the older campervan/caravan where a 3 way fridge was fitted and had a 240v supply - modern compressor fridges are 12v only.

In your case I suspect you have let the battery get to low and the fridge controller has locked out. Keep an eye on your battery level and don't let it get below 50% (as my best guess is you have a lead acid battery)

 

[bethamari]

The fuse is most likely inline as compressor fridges are generally wired as direct as possible to the leisure battery.

If you have one of the all in power units like a Sargent don't get confused by any mains breakers marked as a fridge - these systems are designed for the older campervan/caravan where a 3 way fridge was fitted and had a 240v supply - modern compressor fridges are 12v only.

In your case I suspect you have let the battery get to low and the fridge controller has locked out. Keep an eye on your battery level and don't let it get below 50% (as my best guess is you have a lead acid battery)

Thanks for the reply. Battery hasn’t got low - we have been on EHU the entire time and have solar too etc. and it’s a lithium

 

[roadtripper]

Thanks for the reply. Battery hasn’t got low - we have been on EHU the entire time and have solar too etc. and it’s a lithium

In which case I'd spend more time checking the integrity of the power feed. Make sure it's generously sized cable with minimal joints and no damage

 

[Bigsidavies]

I’ve got LiFePo and good gauge cable and mine still occasionally needs the power reset.

 

[bethamari]

I’ve got LiFePo and good gauge cable and mine still occasionally needs the power reset.

First time we’ve had this happen. Don’t suppose you’ve any idea where a fuse roughly would be for the power reset? Never had the fridge out before so not sure how easy it is to move etc.

Will owe a hopefully cold beer at Camper Jam. Or failing that we’ll be bothering everyone on Thurs to look at it cheers!

 

[DXX]

First time we’ve had this happen. Don’t suppose you’ve any idea where a fuse roughly would be for the power reset? Never had the fridge out before so not sure how easy it is to move etc.

Will owe a hopefully cold beer at Camper Jam. Or failing that we’ll be bothering everyone on Thurs to look at it cheers!

The fuse SHOULD be as close to the battery as possible but still be accessible. However there’s no guarantee, big variations in electrical standards in campervan installations.

 

[Drive Wayne]

First time we’ve had this happen. Don’t suppose you’ve any idea where a fuse roughly would be for the power reset? Never had the fridge out before so not sure how easy it is to move etc.

Will owe a hopefully cold beer at Camper Jam. Or failing that we’ll be bothering everyone on Thurs to look at it cheers!

Ours is a Sanjo fridge, same as the Dometic, my first issue was a poor connection behind the fridge. Four self tapper screws, 2 either side of the inside door, remove the 4 little white plugs for access, pull out fridge gently watching out for scratching the floor! Our next problem sounds like yours where the fuse was taken out for a minute. Our fuse is one of 6 in a little 6 way fuse panel in the cupboard under the sink/breadbin right next door to the LB in the base of the wardrobe/tambour zone.
All good now! Good luck!

 

[bethamari]

. Our fuse is one of 6 in a little 6 way fuse panel in the cupboard under the sink/breadbin right next door to the LB in the base of the wardrobe/tambour zone.
All good now! Good luck!

Ace! So we’ve got a lot of fuses on the Sargeant panel. We’ve also got some under the drivers chair near the battery (LiFePO4). 2 years ago at Busfest - none of our electrics were working and Fish (I think! Thank you!) swapped a fuse out under the drivers chair which fixed it.

We thinking drivers chair again or a separate fridge one in the back? Photos attached - please excuse under the seat where we shamefully haven’t cleaned ¯\_(ツ)_/¯

 

[DXX]

Just because the battery voltage is good doesn’t guarantee the voltage at the fridge is high enough. If one of both of the following then there will be a large DC voltage drop.
1. Incorrect cable gauge, too small (mm2)
2. Excessive cable length.

Have a Search there are a steady stream of fridge / leisure battery issues where it’s almost never the fridge which is at fault.

 

[bethamari]

I turned off the main power on our Sargeant power supply again but this time left it for much longer like @Bigsidavies suggested earlier. And we’ve got all blue lights again!

Many thanks for everyone’s replies. Love this community. Off to stock back up again on cheese now

 

[Bigsidavies]

I turned off the main power on our Sargeant power supply again but this time left it for much longer like @Bigsidavies suggested earlier. And we’ve got all blue lights again!

Many thanks for everyone’s replies. Love this community. Off to stock back up again on cheese now

Ace. If nothing else that proves that your fridge is wired through the sergeant unit for future reference.
Although, as mentioned earlier, that could also create a bit of voltage drop and be part of the problem. It’s so infrequent I’d just live with it.

Enjoy the rest of your trip.
I’ll bring a few well curated IPAs to summer camp as sharers.

 

[bethamari]

I’ll bring a few well curated IPAs to summer camp as sharers.

fab! I’ll bring some sours and if anyone fancies anything from any of the Harrogate breweries then shout

 

[bethamari]

Think I may have spoke too soon. Now getting a blue light for a few seconds. Then the second lower light goes to amber, top one flashes red once - gap - red once for a second time - then changes to blue and then repeats.

 

[Bigsidavies]

Single flashes indicates voltage error. So I guess reset it as before and see if you get another day out of it. Get the wiring checked when you get home. Ideally rewire it straight to the LB with a fuse and bigger cable.

 

[bethamari]

Must have been a fluke it having a brief blue light again when turning of the Sargeant. Pulled every fuse in it one by one to realise it actually wired directly to the leisure battery and the fuse is under the drivers chair! Going to try leaving it out for a while and seeing if it has any effect

 

[DXX]

Must have been a fluke it having a brief blue light again when turning of the Sargeant. Pulled every fuse in it one by one to realise it actually wired directly to the leisure battery and the fuse is under the drivers chair! Going to try leaving it out for a while and seeing if it has any effect

If you have one of the all in power units like a Sargent don't get confused by any mains breakers marked as a fridge

The labels on the Sargent should be disregarded, just. Standard format that’s rarely used. Confusing.