12v not working on Fridge (1 Viewer)

[Arn1e]

Hi all, I have just purchased a Elnagh super D 102 and everything is fine in it except the 12v feed to the fridge, it works fine on gas and 240v but not on 12v, there is a wire that says D+ but there is no power at the connection, does anyone have any wiring diagrams or information about this vehicle, thanks Arnie

 

[bigtwin]

When you checked the D+, was the engine running?

Ian

 

[tonka]

Most only work on 12v when the engine is running.. it's for travel to maintain the temp, does not cool.

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[Arn1e]

Yes running and not running

 

[DavidG58]

Yes running and not running

Personally I don't think it does anything worthwhile on 12V when driving, much better to get hooked up before leaving or use on gas, get fridge cold leave door closed till you get where you are going

That said, if bought from a dealer, particularly if brand new you might as well get it checked

 

[namwaldog]

Our Burstner (on a Fiat) has a 20 amp fuse at the +ve terminal of the engine battery that controls 12v power to Fridge

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[DavidG58]

we have also had our D+ relay fail, can you tell if the battery is charging when the engine runs? check voltage or check display if you have one, should be reading over 13V with engine running, if not suspect the relay

 

[Richard n Ann]

Our freezer compartment pulls down from ambient to -14°c on 12v and the fridge was -5c in the bottom. That was on about a 3 hour trip

The 12v element is about the same wattage as the 230v element so it's not surprising it works the same.

 

[scotjimland]

12v cooling is as good at 240v ..

example wattage RM531

Cooling
Rated input power (AC) 125 W
Rated input power (DC) 120 W

on the bigger models..
Rated input power (AC) 135 W
Rated input power (DC) 130 W

On the biggest fridge freezer .. RML 9435

Rated input power (AC) 170 W
Rated input power (DC) 170 W

12v will also bring the temperature down to 4c from ambient.. so it's not just to 'maintain' the temperature

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[Reallyretired]

Sometimes 12v can be more effective than mains. Probably due to more air circulation through movement.

 

[william morgan]

I agree with Richard and Ann, my fridge freezer does not just keep cold food cold it will, on a typical run of 2 hrs, freeze solid and the fridge is cold enough to fill from eskie on arrival at site, if you read the instructions it will tell you that on 12v the thermostat is de-activated so it will get very cold, believe me I once put my hand in the freezer to check and got my hand stuck, much to SWMBO's delight.

 

[tonyidle]

The reason 12v has the reputation of not cooling as well as gas or mains is that most motorhomes (and caravans) in the past used wire that was too thin. It's invariably a long run from the starter battery / alternator to the fridge that requires a fairly heavy cable. If one too thin is used it's easy to lose a couple of Volts. 2v is a large percentage of what's available.

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[DavidG58]

Our freezer compartment pulls down from ambient to -14°c on 12v and the fridge was -5c in the bottom. That was on about a 3 hour trip

The 12v element is about the same wattage as the 230v element so it's not surprising it works the same.

Amazing I can only presume yours isn’t a Dometic, although we have an excellent freezer the fridge section can best be described as adequate

We always start off from mains powered at home so 12V will not have much to do for us, but would not expect a drop in temp at best i think we might maintain temps

 

[Richard n Ann]

Amazing I can only presume yours isn’t a Dometic, although we have an excellent freezer the fridge section can best be described as adequate

We always start off from mains powered at home so 12V will not have much to do for us, but would not expect a drop in temp at best i think we might maintain temps

Yes Dometic. Your description reminds me of our previous problem:

https://www.motorhomefun.co.uk/forum/threads/our-3-way-fridge-saga.160227/

 

[Arn1e]

Thanks for that most helpful. My problem is really with the electrical feed to the 12v side on the fridge, I have a wiring diagram and wiring is red to D+ then white then it goes to a black then connector x6, not sure where the connector is , I think the problem is from the alternator D+ to wherever that goes, the charge light on the van goes out so there must be a feed out of the D+.

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[Saltings]

Had a similar problem with a 3 way Thetford N3175 not charging when running on 12V. It would switch on for 10-15 secs then just flash.
Worked perfectly on EHU or gas.
On checking it out it seems the PCB has gone as power to the fridge is fine.

Does anyone know how to fit a new PCB preferably with wiring diagram, and if it is in the capability of the average Funster!. The PCB is available at "LeisureshopDirect" for approx £117 (+P&P and VAT)
Cheers

 

[mitzimad]

Had a similar problem with a 3 way Thetford N3175 not charging when running on 12V. It would switch on for 10-15 secs then just flash.
Worked perfectly on EHU or gas.
On checking it out it seems the PCB has gone as power to the fridge is fine.

Does anyone know how to fit a new PCB preferably with wiring diagram, and if it is in the capability of the average Funster!. The PCB is available at "LeisureshopDirect" for approx £117 (+P&P and VAT)
Cheers

most pcb use plugs and connectors that will only fit in one place so easy to change if you can acces it i always take several photos before i strart anything electrical

 

[Saltings]

most pcb use plugs and connectors that will only fit in one place so easy to change if you can acces it i always take several photos before i strart anything electrical

Cheers
I will take some pictures, as suggested. Anyone heard of the company - Leisureshop Direct and what they are like? Anyone with an alternative Thetford PCB supplier?

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