Fridge not running on 12v

[Pinto]

We have had the socket on the car checked but the fridge will not run on 12V (it used to). My question is, should the lights in the van (that run off the battery) work when the car is running ? I'm beginning to think it is a problem with the 13 to 7 pin converter we are using.

 

[WoodlandsCamper]

should the lights in the van (that run off the battery) work when the car is running ?

No. The habitation relay in the van will have isolated them.

 

[VicMallows]

I always think it should be called the non-habitation relay 🙁

However, can anyone explain why this function (disconnecting the 'van 12v general electrics when the car is plugged in) was considered necessary/desirable in the first place? The only reason I can think of is that it was considered that the higher voltage when the battery was on charge might damage anything accidentally left switched on ..... but why should it?; everything in the car quite happily puts up with the on-charge voltage (14.4v or so).

 

[Pinto]

When we had the car checked the chap said because we had the air con on, the fan, wipers etc there wasn't enough power in the battery to run the fridge. He connected directly to the feed of the fuse box (split charger) so the split charger had constant feed. The battery is 91 amps on a big 4 x 4 so maybe we need a bigger battery

 

[VicMallows]

When we had the car checked the chap said because we had the air con on, the fan, wipers etc there wasn't enough power in the battery to run the fridge. He connected directly to the feed of the fuse box (split charger) so the split charger had constant feed. The battery is 91 amps on a big 4 x 4 so maybe we need a bigger battery

Your initial query was why the lights (etc) in the caravan did not function when the car was connected. As Woodland Camper explained, this is a deliberate 'feature' (although as per my post above I do not know why).

You have now mentioned the fridge. This is wired via a completely separate circuit (+ and -) back to the car, and it is the car that decides when this circuit is active (usually when the engine is running and when the alternator is charging). I cannot see why the battery size is relevant. If it was all working before (same car and 'van) I suggest that a poor contact in one of the car-caravan connectors is the most likely cause. Quite possibly in the 13pin-7pin converter.

 

[Dustydog]

Hi Pinto
With the vehicle engine running have you checked the power output to the fridge at the car 12S socket and then the adaptor you use through to the fridge itself.
I suspect you you have a dodgy earth. Check and make good all the pin connections male and female. I assume the physical wiring is intact.

 

[tonybur]

May be wide of the mark but, if it's a new car with a factory towbar you may well find that one of the 13 pins is missing. This is standard on factory fit BMW towbar and requires a replacement socket and additional wiring. If this is the case the battery in the caravan will not charge also. From memory I think it's No12 in the socket. HTH.

 

[MikeG2]

If it's a 13 pin setup then I wouldn't be surprised to find it isn't wired in - it happened to us on our X3. Took ages arguing with the dealer before he would cough up to pay for the wiring and socket change.

 

[Hutch]

On my New Sante Fe, the live for the fridge and ATC was, there but the earth was not. When I pointed it out to them, thier reply was , that it didnt need a seperate earth. So I fitted it myself.