BMW Towbar electrics - No fridge pins

Jul 14, 2019
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Having recently bought a 2015 BMW X3 with factory fit electric swivel towbar, I have found that I have fallen foul of the BMW lack of wiring for the fridge. So my socket has no female wiring to pins 10 and 11, nor even female metal sleeves for those pins. I have reviewed loads of threads on here about this, mostly they are quite old. But nowhere have I found any info about what, if any, metal sleeve is available to insert in the plastic socket casing. That would enable me to wire in a fridge/split relay direct from the car battery that is in the boot (by-passing all the compications of BMWs other socket wiring). I think I may have found a female connector that could work.
But before trying that I am asking if anyone has any recent experience of fixing this problem (probably on other BMWs also) either DIY or using an expert fitter?
 

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Jan 20, 2023
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I had the same on a 2016 BMW520D, back then BMW could supply a replacement socket and loom but the cost was eye watering, I’m lead to believe it is no longer available. I didn’t bother in the end as only had the car for 3 years. I did ask an independent fitter but (from memory) the existing BMW loom was factory fitted into the socket meaning replacing the socket onto the existing BMW harness and adding additional fridge wiring wasn’t straightforward.

This was a few years ago so try talking to someone like PF Jones who produce vehicle specific looms for tow bars.
 

Mel

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Mar 17, 2007
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It is up to you but worth considering if it is worth the stress and expense of resolving it. The fridge will only stay cool whilst connected; it won’t cool below ambient unless you have already pre-cooled it. Our van is in storage no chance of that. We just take “fridge stuff” in an insulated bag with a couple of those freeze blocks chucked in. Turn the fridge on once we arrive on site. It works.
Mel
 
Jul 18, 2017
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It is up to you but worth considering if it is worth the stress and expense of resolving it. The fridge will only stay cool whilst connected; it won’t cool below ambient unless you have already pre-cooled it. Our van is in storage no chance of that. We just take “fridge stuff” in an insulated bag with a couple of those freeze blocks chucked in. Turn the fridge on once we arrive on site. It works.
Mel
The other option is of course ice blocks in the fridge. Probably a lot cheaper than having BMW rewire the car. LOL! :ROFLMAO:
 
Mar 14, 2005
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... The fridge will only stay cool whilst connected; it won’t cool below ambient unless you have already pre-cooled it. ...
This is a myth. The fridge will cool down on 12V power, the energy deployed by the 12V element is fairly close to that of the 230V element , and as such the cooling effect can be similar. However its the fact that the caravan is usually being towed when its in 12V power, and its the uncertain air flow through the fridges condenser circuit that can in some circumstances reduce the cooling effect. For this reason its best not to rely on attempting to cool the fridge whilst towing, but in many cases the 12V will reduce the temperature of the fridge.
 
Jul 15, 2008
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.....if the fridge circuit isn't wired on the OP'S BMW then neither is the caravan's battery charging circuit.
The habitation relay on the caravan will also not work causing some 12 volt safety systems to be inoperative when towing.
 
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Mel

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This is a myth. The fridge will cool down on 12V power, the energy deployed by the 12V element is fairly close to that of the 230V element , and as such the cooling effect can be similar. However its the fact that the caravan is usually being towed when its in 12V power, and its the uncertain air flow through the fridges condenser circuit that can in some circumstances reduce the cooling effect. For this reason its best not to rely on attempting to cool the fridge whilst towing, but in many cases the 12V will reduce the temperature of the fridge.
Thank you Prof; I hadn’t realised this. I will stop propagating it. Just for my clarification; are you saying that whilst the towing electrics are theoretically capable of cooling the fridge below ambient from scratch; in practice they are unlikely to effect much more change than maintaining a pre cooled temperature? Suppose it depends on a number of factors?
Mel
 
Mar 14, 2005
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Thank you Prof; I hadn’t realised this. I will stop propagating it. Just for my clarification; are you saying that whilst the towing electrics are theoretically capable of cooling the fridge below ambient from scratch; in practice they are unlikely to effect much more change than maintaining a pre cooled temperature? Suppose it depends on a number of factors?
Mel
There are two factors that make the biggest difference, the first is the degree of air movement through the caravans fridge grills when towing. Arguably if you put the covers on the grills it may help except in really hot weather. But physical shape of each outfit will affect the degree of air movement through the fridge grills - aerodynamics.

The second factor which is more likely to be an issue now than previously is the use of smart alternators in cars which can restrict the availability of12V delivered to the caravan whilst towing.

I have to say that over the years I caravanned, I never had a problem with the fridge cooling whilst towing, but even then we always precooled or used ice blocks, and we always found the ice box was producing frost.

I suggest each caravanner tries it for themselves, - put a thermometer in the fridge, and do a journey and see if or how much cooler the fridge is after the journey.
 
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Oct 31, 2022
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I have a BMW factory fit towbar on a late 2019 X3. I do have the required pins. However, my fridge does not work as it seems that it is not getting enough power. I assume this is loss over the wires in the van as at the towbar it is sufficient. This seems to be fairly common with the tall Thetford fridges.
 
Apr 10, 2019
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I've a tall dometic in my Bailey Alicanto Grande Faro towed by a 2013 Vw touareg and same issue. Apparently when I questioned the 12v not working properly when towing due to the fridge warning lights flashing red after about ten miles, my dealer says it still chills via 12v albeit at a lower rate. We chill the fridge freezer down on maximum on gas the day beforehand and never had an issue with the contents defrosting or even getting anywhere near warm in regular seven or eight hours trips to Cornwall.
 
Jul 14, 2019
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Thanks to all for replies so far. Unfortunately nobody with a specific answer. I will give my heath robinson fix a go sometime and I'll come back here with the result.
On the subject of cooling on 12V while towing, all I know (and want again if possible) is that during many years of touring across Europe, often on the road in 30 degress plus for hours on end, there is still plenty of the hard stuff in the ice box for my wifes gin and tonic on arrival. Yes we start and end on a hook up, but never any problems in transit. I'm sure the ice packs etc alternative may work, but it just isn't as convenient - for us. Having said that, if needs must later on we'll give it a go.
Milkfloat - Are pins 10 and 11 wired in though? If they are your 12 V power to the fridge will be due to the "smart" alternator reducing voltage output to only keep the the battery at about 80% charge. The result can be insufficient voltage to run the fridge.
 
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Jul 18, 2017
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Although all our previous cars have been wired for the fridge cooling, sadly on 12v it was almost ineffective. I bought a thermometer and placed it in the fridge and by the time we got to our destination the temperature inside the fridge had increased. The fridge was empty and it was a warm day. I repeated this on several occasions and the results were always the same.

I also experimented with a fridge that was full of cold foods and the freezer packed. The temperature remained approximately the same for the duration of the journey.

With our current vehicle I did not bother with having the wiring for fridge fitted and we have had no issues and not missed having it.
 
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Thanks to all for replies so far. Unfortunately nobody with a specific answer. I will give my heath robinson fix a go sometime and I'll come back here with the result.
On the subject of cooling on 12V while towing, all I know (and want again if possible) is that during many years of touring across Europe, often on the road in 30 degress plus for hours on end, there is still plenty of the hard stuff in the ice box for my wifes gin and tonic on arrival. Yes we start and end on a hook up, but never any problems in transit. I'm sure the ice packs etc alternative may work, but it just isn't as convenient - for us. Having said that, if needs must later on we'll give it a go.
Milkfloat - Are pins 10 and 11 wired in though? If they are your 12 V power to the fridge will be due to the "smart" alternator reducing voltage output to only keep the the battery at about 80% charge. The result can be insufficient voltage to run the fridge.
Yes - they are wired in and the fridge does not work even when the alternator is having to work hard. Lights on and battery packs being charged.
 
Oct 7, 2023
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Having recently bought a 2015 BMW X3 with factory fit electric swivel towbar, I have found that I have fallen foul of the BMW lack of wiring for the fridge. So my socket has no female wiring to pins 10 and 11, nor even female metal sleeves for those pins. I have reviewed loads of threads on here about this, mostly they are quite old. But nowhere have I found any info about what, if any, metal sleeve is available to insert in the plastic socket casing. That would enable me to wire in a fridge/split relay direct from the car battery that is in the boot (by-passing all the compications of BMWs other socket wiring). I think I may have found a female connector that could work.
But before trying that I am asking if anyone has any recent experience of fixing this problem (probably on other BMWs also) either DIY or using an expert fitter?
 
Oct 7, 2023
2
0
510
Visit site
Having recently bought a 2015 BMW X3 with factory fit electric swivel towbar, I have found that I have fallen foul of the BMW lack of wiring for the fridge. So my socket has no female wiring to pins 10 and 11, nor even female metal sleeves for those pins. I have reviewed loads of threads on here about this, mostly they are quite old. But nowhere have I found any info about what, if any, metal sleeve is available to insert in the plastic socket casing. That would enable me to wire in a fridge/split relay direct from the car battery that is in the boot (by-passing all the compications of BMWs other socket wiring). I think I may have found a female connector that could work.
But before trying that I am asking if anyone has any recent experience of fixing this problem (probably on other BMWs also) either DIY or using an expert fitter?

I have a Sterling Wildside caravan specific battery to battery charger fitted in the caravan, its main function is to combine the pin 9 and 10 feeds from the car to optimise battery charging or fridge operation by ensuring the voltage and current supplied by the car are at the optimum values, over coming the deficiencies of the Euro 6 alternator. It has an additional Wildside function that allows you to operate the fridge from the leisure battery. Baring in mind the absorption fridge will draw 9-11A continuously that can rapidly deplete your battery especially if it's a lead acid. I do use the function for maintaining the fridge whilst on a ferry crossing of a few hours knowing that I have a 125A LiFePO4 battery and the battery will be being properly charged when towing the other side.
For normal fridge use I would go see an auto electrical and get them to run a suitable 15A feed direct from the battery to the trailer socket via an ignition switched relay. `it probably won't be cheap on labour as they will have to dismantle lots of trim to run the +ve cable
 
Sep 21, 2022
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Having recently bought a 2015 BMW X3 with factory fit electric swivel towbar, I have found that I have fallen foul of the BMW lack of wiring for the fridge. So my socket has no female wiring to pins 10 and 11, nor even female metal sleeves for those pins. I have reviewed loads of threads on here about this, mostly they are quite old. But nowhere have I found any info about what, if any, metal sleeve is available to insert in the plastic socket casing. That would enable me to wire in a fridge/split relay direct from the car battery that is in the boot (by-passing all the compications of BMWs other socket wiring). I think I may have found a female connector that could work.
But before trying that I am asking if anyone has any recent experience of fixing this problem (probably on other BMWs also) either DIY or using an expert fitter?
I had exactly the same issue on 2017 Porsche Cayenne, also with a factory fitted electric swivel there was no insert to fit and Porsche make things very difficult for third party companies to touch factory fitted equipment. I had to bite the bulitt and have a new plug fitted very expensive but works fine.
 

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