Fridge wont run when towing

[NEW2IT]

Hi Everyone,

Im new to caravanning, bought a Abbey Adventura in November and took it out this weekend to Buxton to try it out and figure out all the buttons and switches. I sorted most but I have one issue if you could help.

When I towed the caravan I made sure the switches in the closet were all off (Space heather, Water Heater, Battery Charger and Pump) and the little black switch was switched to Car, I then switched the Thetford Fridge onto the battery symbol and drove off.

When I got to buxton after approx. 1hr 20min I looked at the battery charge meter which was in the green then switched the black button to VAN and noticed the battery charge meter jumped down to below the green is this right?

Also when I packed up on Sunday I did it all again, all red switches off and the black switch to CAR but also noticed the light inside the fridge stayed off when you opened the door, does this mean the fridge isn't running whilst im towing or am I doing something stupid.

I also tried to run the fridge using gas on Saturday (just to see if it was working) and all I could hear was constant clicking, but I remember that I just turned the knob to the gas symbol and didn't hold it in, should I have held it in to light it like you would when lighting a gas fire???

Any words of wisdom would help.

Wayne

 

[audiorob]

The 12v supply from the car should only operate to run the fridge and charge the caravan battery when the engine is running - the electrics being protected by a relay to prevent the caravan flattening the car battery when parked up. If you have a meter you could check that there is supply while the engine is running.
I am assuming that you have either a 13 pin jaeger plug, or the original 12N Black (essential wiring for roadlights) and 12s Grey (Supplementary circuits) connected.
The gas to the fridge could have it's own isolator valve (mine for all alliances are beneath the oven and as I don't use the fridge on gas I leave mine 'off') so make sure this is open. You would have to hold the gas knob until the fridge is lit - like the thermocouple on a hob it prevents gas escape if the flame goes out.
Hope this is a starting point for you!

 

[NEW2IT]

Hi,

Thanks for the reply, when I noticed this the car was hooked up and the engine was on, I dont have a meter and wouldnt know where to test the supply.

I will try to light the fridge with gas next time im at the van, thanks

Wayne

 

[Woodentop]

Switch the caravan internal lights on with the power switched to caravan, check the voltmeter.
Plug the 13pin into the car - if you have Alko ATC the brakes should cycle and the LED on the hitch will light - don't worry if it is red or green at this stage.
Start the car engine and blip the throttle.

If the interior lights go off when you plug into the car the correct relay is switching but there is no 12V getting from the car into the caravan 12V circuits so check the fuses in the caravan. If they stay on check the voltmeter which should be rather lower than the initial reading. If it is about the same then check for 12V between pins 9 (+ve) and 13 of the car socket.

If the interior lights go off when you start the engine then all should be well: if they do not then you have no fridge supply on pins 9 and 10 of the car socket. Pin numbers and location are on the inside of the socket lid.

If your car has never been used with a 13pin connection before it begs the question of whether the fridge wiring has been installed - on cars made in the EU such as VAG and BMW this wiring is an extra and has to be specified when the towbar is fitted.

 

[Dustydog]

If you are using the older 12s grey plug for supplementary charging then it is possible the Earth pin is corroded or burnt out. This will cause a lack of power to the fridge with the engine running.check both the socket and plug.
Even when working in good order the 12 volt system will keep the fridge cool but not chill it down the same as on gas or mains electric. Always best to chill the fridge down a day or so before departure.

 

[ProfJohnL]

If you are using the older 12s grey plug for supplementary charging then it is possible the Earth pin is corroded or burnt out. This will cause a lack of power to the fridge with the engine running.check both the socket and plug.
Even when working in good order the 12 volt system will keep the fridge cool but not chill it down the same as on gas or mains electric. Always best to chill the fridge down a day or so before departure.

This comment needs further clarification. Virtually all caravan fridges have the option to run on Gas, Mains 230Vac or 12Vdc when the cars alternator produces more power than the car needs.

Which ever fuel has been selected, it simply produces roughly the same amount of heat in the same region of the refrigerators cycle, and as such the refrigerator doesn't mind which fuel is used, and any of them will cause the fridge to cool down, but, the main difference between operation on 12Vdc compared to Mains 230V or Gas is the 12V supply is not normally used for long periods, generally only whilst the caravan is being towed, so it doesn't have much time to make a big difference to the temperature, consequently 12V is not normally available long enough to fully cool the fridge.

As Dusty says, It is preferable to pre cool the fridge using Mains or Gas before towing, and to also pre cool the items you put into it.

 

[David_A]

I had this same problem.
Bought a cheap 13 pin socket tester, which showed that no switched live supply was available for the fridge circuit.
Found a blown fuse in the SAM unit in the car boot - replaced same and the problem was solved.

 

[Hutch]

Newtoit, I had a 2013 Coachman, stiĺ have it , changed the car to a Brand Spanking new Hyundai Sante Fe, factory fitted towbar and electrics, hooked up the caravan, no power to the fridge or the atc. There was no earth return from the caravan through the 13 pin Jager connecter. Fitted the correct return earth, all good.

 

[chrisn7]

New21T - If you have a 13 pin set up, its well worth getting yourself a socket tester, which confirms correct functions of all road lights, fridge, permanent live, etc.at the car. This quickly isolates a problem to car or van saving a lot of head scratching...

 

[TomB]

I have a thetford N3142 fridge in our Adria 512 UP.
Would not run on 12 V whilst being towed.
The problem was the gauge of the 12V wiring from the car battery to the caravan.
This fridge takes 200W (8 Amps at 12 V). Together with the ALKO ATC and some electronics in the caravan that can't be shut off, the load causes a too important voltage drop over the 2.5mm2 12V line. And the frige electreonics measure the voltage, and will block 12V operation if the voltage drops below 10.8V - 11 V.
Has the line replaced with a 4mm2 wire, and this solved the problem.

 

[otherclive]

I had this same problem.
Bought a cheap 13 pin socket tester, which showed that no switched live supply was available for the fridge circuit.
Found a blown fuse in the SAM unit in the car boot - replaced same and the problem was solved.

Which tester did you buy? Sounds a useful addition to the armoury already carried.

 

[Anseo]

I am going to buy a tester and this looks like it can do the job:

https://www.aliexpress.com/item/Car-7Pin-13Pin-Towing-Lights-Wiring-Trailer-Circuit-Plug-Tester-Socket-Set-for-Auto-Trailers-Caravans/32974106097.html?spm=a2g0o.cart.99999999.278.32573c00v7jptI

 

[mogarage]

You don't say what you are towing with - but be aware that many German manufacturers don't include the fridge wiring in a factory fit towbar