Test if fridge 12 volt working. Also connecting fridge direct to house battery.

J_KZ-1 · Veteran Member

Test if fridge 12 volt working. Also connecting fridge direct to house battery.

Possum3 · Guru

John my advice would be to change connection from 12pin plug to a stand alone heavy duty Anderson type - fridge current draw is too much for current set up.

Many vans have undersize wiring (and over-length) as well.

I'm sure some on here would advise a total rewire.

As I am unaware of your van manufacturer's methodology I would not advise any modifications.

I am unsure whether any of Caravan Council technical advice sheets may talk about this problem www.caravancouncil.com.au/ (free downloads).

J_KZ-1 · Veteran Member

Thanks for the reply Possum,

I been looking at the bloody wiring today and decided to stick to the limited wiring I know i.e. wiring up the seven pin on the 8x5 trailer and boat trailer, ealso the 12 pin on car and van in an emergency. Its a jumble of wires in and underneath the van.

Therefore, Im the biting the bullet, and will taking both car and van to a 12/24 volt sparky when I can book them in. That way, if something goes wrong with the wire on the way up to the cape and back down visit family in Tin Can Bay and Grafton. I wont have to listen too: I told you so, you shouldve taken it to an electrician, from my dear, adorable, wife of over 40 years.

Thanks for your input mate.

-- Edited by J_KZ-1 on Tuesday 6th of June 2023 01:36:34 PM

Bobdown · Guru

John, ask the auto-electrician about an Anderson plug, it's the way to go........ cheers Bob

Whenarewethere · Guru

I get the impression you are running a gas fridge. They draw a lot more than a compressor fridge & continuously instead of intermittently.

Plugs actually use heavy gauge wire to dissipate heat from the resistance in plug connections. Even an Anderson plug with thicker wiring has a higher capacity than the same plug with thinner wiring, putting length of wire issues aside.

As others have suggested run a separate Anderson plug for power. Also work out the total length of + & - for the resistance. It is surprising how much voltage drops.

If you do run the fridge directly from the caravan fridge. Maybe do it via a relay & warning system so you don't forget to switch to gas to avoid flattening your batteries. Gas fridges suck too much power.

Mamil · Senior Member

As 3-way fridges pull about 16A at 12v, and then there's charging your battery as well, you could easily be up to 30-40A on the one cable so I'd recommend 16mm2 wiring between car battery and caravan.

And as 7-pin and even the larger contacts on a 12-pin can't handle that wire size or current flow you should use a 50A Anderson plug as others have suggested.

Otherwise, running the fridge off your van battery is a reasonable alternative but I'd still suggest 10mm2 wiring between battery and fridge as volt drop is the most common cause of 3-way fridges under-performing on 12v.

Then add either a 'fridge switch' or ignition triggered relay to disconnect the fridge when there's no charge source available, otherwise it's a great way to run your batteries flat while you stop for a long lunch!

Fridge switch.jpg

-- Edited by Mamil on Tuesday 6th of June 2023 08:46:54 PM

J_KZ-1 · Veteran Member

Apologies for the delayed reply, havent had access to iPad for a few days.

Yes we do have a gas, 240v & 12 volt fridge. I decided to byte the bullet and went and had a catch to Auto elec guy, like all your helpful comments, he stated that the connect to caravan house battery is one alternative, but he recommended a seperate Ando plug setup for the fridge as being a better option.

Ive made arrangement with him to go the Ando plug setup. Ill be dropping off the car and van to him in a couple weeks when I return to Melbourne.

Thanks to everyone for their advice and input.

Once again thanks to all,

John.

PS, Ill also look into the switch attachment.

-- Edited by J_KZ-1 on Thursday 8th of June 2023 08:38:11 PM

Whenarewethere · Guru

Make sure the electrician is using 6awg wire.

Also the ends including Anderson lugs have heatshrink tube.

You only want to do the job once.

J_KZ-1 · Veteran Member

Thanks for the input: whenarewethere,

Will be checking that he does do it right! learnt the hard way back in 2021 when we managed to beat the last lock down in Vic that year, had to fix up some shonky Ando plugs (by auto elect on the Mornington peninsula: recommended by OurVan caravan sales) set up while on the road that year for 5months in NT & WA. Bloody things fell out of connectors and also coonectorson mppt charger.

The Bastard in M.Peninsula, used 6awg at Ando plug end and battery end for short run then spliced 6m2 in between in the cable running through chassis. This was picked up by my son-in-law when we got back to VIC.

This time, Ill be driving up to Melbourne to get it fixed, as we leave the van in Melb. and taking it to a chap who look after my LR D2 when I use to go up to visit family prior to getting the LR D3 12 plus years ago, he did a great job then, he has a good sparky on hand and checks the works.

I must add, as I have limited electrical knowledge I did get a lot of good advise from you and others on the GN Forum back in 2021 re setting up for our escape back then

Thanks, John

PS I be posting a question on how to check if the 12 volt is working on our old 3way fridge. In the van

Roger Roger · Veteran Member

Hi The only way of knowing if a 3 way frig is switching over to 12 volts is to actually measure the current flowing to the element. They do not sense the current, only turn the relay on. Our motorhome has an old style meter and I check occasionally after starting the truck engine that the power is being drawn , in our case 21 amps. Enough power to melt standard fuse and plugs over 7 hour drive. Do need regular checking to ensure it is working I beleive explains why reports of frig not working on 12 volts.

J_KZ-1 · Veteran Member

Thanks for the input Roger,

Ours doesnt have a meter, so Ill try a multi meter. Ours is a 2003 Dometic RM 2350 model, almost as old as me.

Thanks again Roger.