12V Socket B Pillar Dometic CFF12 fridge fault

[jimmywease]

Apologies for the lengthy post but having searched and read about similar issues, I wanted to be very specific and avoid conflation.

I recently purchased a Dometic CFF12 fridge and plugged it into the passenger side B Pillar 12V cigar-lighter style outlet on my MY2017 Beach.

I used the ‘Low’ setting on the CFF12, as recommended for running from a leisure battery.

After a few months of occasional fridge use on day trips, I noticed that often (usually when the engine is off) the fridge light turns orange (constant) and the fridge compressor halts, allowing the fridge to warm up, way above the correct temperature.

At first, I assumed that this was an issue of poor leisure battery voltage/performance, although the orange light should apparently have been be flashing, to indicate low voltage, which was not observed.

The voltage at this outlet and the outlet at the sliding door cupholder were both reading 12.8V hence low voltage shouldn’t have been an issue.

Upon further testing, this fridge cutting-out problem is exclusive to the B Pillar socket. The fault is persistent from the B Pillar socket but cannot be replicated from the sliding door socket, or from the socket next to the gear lever (ignition battery 12.5-12.0V during test).

Could it be fuse related (although the B Pillar socket reads around 12.8V with engine off, most of the time)?

The socket has a bit of ‘give’ in its housing. Although the fridge plug is held firmly in the socket, once connected, the socket itself has a couple of mm of spongey (not loose) movement in its housing. Could the connection behind the socket be faulty?

Could there be an issue with the electrics behind the socket, perhaps related to past (inevitable) water ingress from sliding window, which filled the bottle-holder to the left of the socket?

 

[Ch1pbutty]

You need to run a nice thick dedicated fused feed / socket from the leisure battery. The factory VW 12v wiring to the socket is cheap and thin so cannot always handle the load, which results in fluctuations to the fridge temp.

It’s easy to do, the wire can be hidden/pushed under the plastic trim on the floor using a trim tool (or teaspoon!).


AAOTOKK Cigarette Lighter to SAE... https://www.amazon.co.uk/dp/B0813P4JHV?ref=ppx_pop_mob_ap_share

GTIWUNG 16AWG Quick Disconnect... https://www.amazon.co.uk/dp/B07YXQM5D7?ref=ppx_pop_mob_ap_share

 

[Perfectos]

I run a cfx 35 from that socket regularly , for day / weeks at a time (solar panel on roof).

I doubt fuses are the issue , however worth checking IMO.

The fuses for the 12v sockets located behind the drivers / passengers seat are (three of them in a Beach: B pilllar, cup holder c pillar, in boot) are located under the passenger seat (U.K.) turn the passenger seat through 90 degrees to assist in access (you will need to slide the seat backwards as far as possible whilst allowing the seat to be turned through 90 degrees. )

You will see three 15amp fuses grouped together, in the front fuse holder. Check all are seated correctly.

The issue may be that the 12v cigarette lighter is not seating correctly into the socket? I.e. slightly popping out causing a bad connection?

It is possible to remove the socket from the B pillar it is in two section , the outer section is fixed to the inner section and requires a particular way to remove and separate (Google / youtube will assist in how the remove and separate both parts if required) take care not to damage the socket.
The cables plug directly onto the rear of the socket, it could be possible that they have become corroded through water ingress and therefore have a higher resistance.

As mentioned above , hard wiring to the LB is possible- search the forum for other threads.

Another possibility is the air vents on the fridge become covered / partially blocked and the unit cannot cool properly, the fridge will simply shut off until the electrics cool down sufficiently. (I have had this happen once - orange light , increase in internal temp above the set temp, solution, uncover the vents, restart the fridge, hey presto )

Shout if you need help finding the threads / YouTube vids etc.

 

[jimmywease]

You need to run a nice thick dedicated fused feed / socket from the leisure battery. The factory VW 12v wiring to the socket is cheap and thin so cannot always handle the load, which results in fluctuations to the fridge temp.

It’s easy to do, the wire can be hidden/pushed under the plastic trim on the floor using a trim tool (or teaspoon!).


AAOTOKK Cigarette Lighter to SAE... https://www.amazon.co.uk/dp/B0813P4JHV?ref=ppx_pop_mob_ap_share

GTIWUNG 16AWG Quick Disconnect... https://www.amazon.co.uk/dp/B07YXQM5D7?ref=ppx_pop_mob_ap_share

Thanks for all the information. If I can’t get the socket working properly, I’ll certainly go for this solution.

 

[jimmywease]

I run a cfx 35 from that socket regularly , for day / weeks at a time (solar panel on roof).

I doubt fuses are the issue , however worth checking IMO.

The fuses for the 12v sockets located behind the drivers / passengers seat are (three of them in a Beach: B pilllar, cup holder c pillar, in boot) are located under the passenger seat (U.K.) turn the passenger seat through 90 degrees to assist in access (you will need to slide the seat backwards as far as possible whilst allowing the seat to be turned through 90 degrees. )

You will see three 15amp fuses grouped together, in the front fuse holder. Check all are seated correctly.

The issue may be that the 12v cigarette lighter is not seating correctly into the socket? I.e. slightly popping out causing a bad connection?

It is possible to remove the socket from the B pillar it is in two section , the outer section is fixed to the inner section and requires a particular way to remove and separate (Google / youtube will assist in how the remove and separate both parts if required) take care not to damage the socket.
The cables plug directly onto the rear of the socket, it could be possible that they have become corroded through water ingress and therefore have a higher resistance.

As mentioned above , hard wiring to the LB is possible- search the forum for other threads.

Another possibility is the air vents on the fridge become covered / partially blocked and the unit cannot cool properly, the fridge will simply shut off until the electrics cool down sufficiently. (I have has this happen once - orange light , increase in internal temp above the set temp, solution, uncover the vents, restart the fridge, hey presto )

Shout if you need help finding the threads / YouTube vids etc.

Thanks very much for this. I’ll try to get onto it next week, when I’m less busy. I’ll report back.

 

[jimmywease]

I run a cfx 35 from that socket regularly , for day / weeks at a time (solar panel on roof).

I doubt fuses are the issue , however worth checking IMO.

The fuses for the 12v sockets located behind the drivers / passengers seat are (three of them in a Beach: B pilllar, cup holder c pillar, in boot) are located under the passenger seat (U.K.) turn the passenger seat through 90 degrees to assist in access (you will need to slide the seat backwards as far as possible whilst allowing the seat to be turned through 90 degrees. )

You will see three 15amp fuses grouped together, in the front fuse holder. Check all are seated correctly.

The issue may be that the 12v cigarette lighter is not seating correctly into the socket? I.e. slightly popping out causing a bad connection?

It is possible to remove the socket from the B pillar it is in two section , the outer section is fixed to the inner section and requires a particular way to remove and separate (Google / youtube will assist in how the remove and separate both parts if required) take care not to damage the socket.
The cables plug directly onto the rear of the socket, it could be possible that they have become corroded through water ingress and therefore have a higher resistance.

As mentioned above , hard wiring to the LB is possible- search the forum for other threads.

Another possibility is the air vents on the fridge become covered / partially blocked and the unit cannot cool properly, the fridge will simply shut off until the electrics cool down sufficiently. (I have had this happen once - orange light , increase in internal temp above the set temp, solution, uncover the vents, restart the fridge, hey presto )

Shout if you need help finding the threads / YouTube vids etc.

Fuses look fine.

Can’t see video for this specific 12V socket type. Plenty for other types, that require specific removal tool (which I can’t find for this model).

If you can point me in the direction of a YouTube video for socket removal, that would be great.

Thanks

 

[Perfectos]

There are two clips holding the inner metal sleeve into the outer ring.
9 o clock and 3 o'clock position.

Edit note the inner part can rotate so the tabs may be in different positions

Using a small screwdriver carefully depress the plastic clip on one side , you need to insert a thin trim tool or a plastic card finger nail etc into the slight gap between the metal sleeve and the outer plastic ring, this will put forward pressure on the tube, with the trim tool / card/ finger nail still inserted depress the other tab ( don't worry too much if you do bend the metal slightly you can adjust it after the tube come out, just don't over do it) , you should then be able to withdraw the metal tube insert. It's a real fiddle but it does come out.

The socket is permanently live, so be careful not to short it out. (Fuse under seat)

 

[Perfectos]

Here is a vid , it shows the components and how they fit together , it also shows the correct tool if you want to buy it

 

[Perfectos]

Here without the proper tool, but you'll get the idea

 

[jimmywease]

Update:

I bought the removal tool on Amazon: https://amzn.eu/d/dzDozYD

I removed the socket, and as I did so, the earth connection at the back fell off.
Both connections seemed pretty loose, so I gave them a squeeze with pliers, to crimp them together a bit.
Inevitably I shorted it and blew the fuse!
After reassembling the socket and replacing the fuse, the same fault remains: CFF12 cuts out when connected to the B pillar 12V socket; works fine from sliding door 12V socket.

Interestingly, whilst testing from the ‘good’ socket, I finally observed the low voltage cut-out on the fridge, which indicates differently to the ‘bad’ socket fault. At low voltage, the orange light flashes at least once. With the fault, it is always constant.

I may have to go with the direct battery connection solution, although it will bug me that there’s an issue with this socket. Can anyone advise on exposing rest of the route of the B pillar 12V socket cable route, to the the battery?

 

[Perfectos]

Mmmh
The connectors should both have a plastic sheath as in photo 1
In photo two seems to only have one ?
The crimp on the earth cable looks to not be a clean crimp to bare cable ? See mark up
Possibly an issue with intermittent earth ?
Edit: I wonder if the earth is the trigger to tell the fridge that the battery wiring has an issue and therefore puts it into a safety mode (unlike low voltage mode setting)

The route will be down the back of the panel , exit By B Pillar, route under carpet to fuse board - you'll know which fuse it is as you've blow that one already. Well worth checking the earth points and continuity. There are several earth points located by the front seats, I'll dig out a photo of the front floor pan which shows those points.

Edit- floor pan photo added - the earth points are visible

Thanks for posting the details of the socket removal tool, it'll help other in future.

 

[jimmywease]

Mmmh
The connectors should both have a plastic sheath as in photo 1
In photo two seems to only have one ?
The crimp on the earth cable looks to not be a clean crimp to bare cable ? See mark up
Possibly an issue with intermittent earth ?
Edit: I wonder if the earth is the trigger to tell the fridge that the battery wiring has an issue and therefore puts it into a safety mode (unlike low voltage mode setting)

The route will be down the back of the panel , exit By B Pillar, route under carpet to fuse board - you'll know which fuse it is as you've blow that one already. Well worth checking the earth points and continuity. There are several earth points located by the front seats, I'll dig out a photo of the front floor pan which shows those points.

Edit- floor pan photo added - the earth points are visible

Thanks for posting the details of the socket removal tool, it'll help other in future.

View attachment 137443

View attachment 137444

In photo 2, I’ve removed the plastic sheath (easily detachable plastic housing, with two tiny fasteners) in order to crimp the female contacts slightly, to improve the connection and prevent them coming apart. I did this to both connectors. I suppose photos 1 and 2 should be reversed, to make more sense.

I’ll take another look at it when I get time. I was convinced that I had cured the issue on this occasion and didn’t have time to try again, when the fault remained.

Glad I have the socket removal tool. It’s an awkward location and my reading glasses are out of date. I almost certainly would have damaged the socket with two screwdrivers!

 

[jimmywease]

I took it apart again and the wire connections to the spades looked fine (pictured). I also checked earth continuity from the wire; the spade and the connected socket (to seatbelt bolt) and they all seemed okay.

The cable runs vertically upwards, through the B-pillar, presumably to join the bundle in you picture, running back down in front of the seatbelt.

 

[Perfectos]

Hard wire a connection direct to LB, you'll be chasing that issue forever IMO

Is it worth trying the Known good other socket from the Cpillar ,
i.e swap them over to discount the socket having an issue ?