12volt fridge running off the car

[DonaldMcK]

Hi Returned from holiday. Had the battery switch on, on checking with engine running the light built into the switch was pulsating on and off. When we arrived home the fridge had defrosted.
Anyone else had the same problem and what is the cure if any?

ALso looking for a new front window mine cracked right across while traveling, Caravan is a ABI Monza 400D mk2. 1992. Window size is 165cm x 86cm. anyone know of or have one for saleplease?
Thanks

 

[ProfJohnL]

Hello Donald, and welcome to the forum.

The first thought is the 12V heating element could have failed. with the obvious consequence you have had, but its not a foregone conclusion as there are several other factors that can affect the function of the fridge.So the thing to do is if feel confident enough to try, is to measure the dc resistance of the 12V coil It should have a value of around 1.2 to 1.5Ohms. much more or open circuit then it points to a failed element.

Your fridge is now 24 years old and even though the system is usually very well sealed, there can be regenerant losses over time. Certainly the cocktail of fluids the use inside the coils can deteriorate and along with other environmental factors the fridge will loose efficiency over time. ,

The absorption method of cooling is great for caravans as its virtually silent, but it's not as efficient as a compressor driven fridge like the ones you have at home. Absorption fridges can usually manage to drop the inside of the fridge by between 20 to 30C but they are also more sensitive to ambient temperatures which will make them loose efficiency as the temperature differences of the heat exchanger coils to the ambient air reduces.

Another factor that will apply when towing, is the force of the wind that can get in through the fridge vents will increase the airflow around the fridge and if the air is warm it will increase the work the fridge has to do to keep things cold.

When travelling, the increased air flow around the heating element may rob some of its efficiency as will increased air flow around the walls of the fridge which fridge may also increase the heat input through the walls from the warmer air.

Don't forget the fridge is a gas burning appliance and for your own safety and that of your family, etc, the appliance should only be installed serviced or removed by a person who is fully competent with LPG gas fitting and testing.

 

[Gafferbill]

..........are you sure you actually turned the 12 volt feed to the fridge to the "on" position via the correct red rocker switch.
A pulsating red light from the rocker switch suggests you may have turned the gas igniter switch on by mistake.
These two red rocker switches are almost identical on the fridge that was commonly fitted to caravans of your vintage.

 

[DonaldMcK]

Thanks for the info will have to have the fridge checked. The way it is going the van looks destined to go though. What with the fridge ,window and other small but time consuming faults.

The right rocker switch was turned on it has battery on it ,the gas igniter switch is at the far end of the panel.

 

[chrisbee1]

Depending how your car is wired another possibility is the relay in the 12S power supply. If the car voltage is just at the switching voltage then the power supply to the fridge will be switching on/off and the fridge power switch will flash. Checking the car's socket for a constant feed to the fridge would be my first check.

 

[Woodentop]

It would be useful to know the type of car and socket connection. If the car has 13pin (with a 12N/S adapter) it may not have fridge wiring fitted unless it was specified on installation and especially if it is not a UK car. The supply should be on pins 10(+ve) and 11 (-ve) - the pin numbers are moulded into the inside of the socket cover - and should be around 13-14V when the car engine is running but zero (or very low) when the engine is stopped. Conversely pins 9 and 13 which are battery should be live all the time.

An old trick with fridges that are not working properly is to take it out and stand it upside down for a day or so, the reinstall it. You'd be surprised how often that fixes it!

 

[DaveA1]

Had the same problem when I towed with a Vauxhall Cavalier, relay supply wire section was too small, coursing a big voltage drop.
Cured it by replacing it with 4mm (all I had at the time) direct from the battery, through a 20 amp fuse, to the relay, bit overkill 2.5mm would have been enough, stopped the light flashing though. B) B)