Thread: Running Camper Fridge from Disco 4 Plug - from a Newbie

Originally Posted by RosscoDisco

I have just installed Traxides Aux batt kit for the aux batt in the rear of the car (for Engel Fridge/freezer) and to run out to charge the batteries in the Camper.

I understand that it may be possible to also run a second cable from the Camper's fridge to the back of the Disco (via an Anderson plug) which connects to a wire taken out of the 7 pin plug.

G'day Rossco, welcome to AULRO from another recent member - loads of really helpful people on this forum. One of them is Tim - "drivesafe" on here - from whom you'll have bought your Traxide kit. When I fitted mine recently, I went with the option of adding an Anderson plug which tucks into the panel behind the bumper where the towing electrics are located when it's not in use. Did you not do that with yours? That would have given you a full power Anderson socket you could have used for your caravan fridge if you added a dedicated cable. If you didn't, just e-mail Tim and explain what you want to do and he'll send you the bits. I made a couple of non-standard mods to my installation and he was really helpful in advising on the cable required and sending me that plus various connectors, fuses and bits and bobs I needed. Cheers, Gavin

Thanks for the Reply Gaviatrix - Sounds like we've both installed the same kit - the Kit 5 which includes the Anderson Plug that provides power to the Camper. Mine will be connected back to the deep cycle Camper 'house' batteries to charge them.

I have been pestering Drivesafe Tim about this quite a bit (and you are right he is super helpful) and he put me on to the second cable option for the fridge (and i've bought the gear for it too) but he wasn't 100% on the 'black wire' at the 7-pin plug and suggested that i post a question on this forum.

Ah right! Now I'm clear, but not able to help, sorry. I'm sure others here who will be able to advise will chime in. Good luck with it!

Dont touch the factory wiring! The wiring for the trailer plug does not match what you want & is also too small.
The Black wire you talk of is actually the "Park Light" circuit.

Normally an Anderson plug runs from the battery (Main or 2nd depending on owners requirements) & the cable size from the battery to the plug itself is usually either 6B&S or 8B&S. I normally run 8B&S with a 30Amp fuse.

Seeing that your 2nd battery is in the rear, you can run the wiring from the rear 2nd battery to the trailer connector under the bumper. Then make the same connection on the trailer & connect them to charge the fridge.

Cheers & Yes Tim is extremely helpful, patient & understanding.

Dear Sniegy - many many thanks for the reply.

What you say makes sense. I had silently wondered if the cable size at the plug would be large enough to make any difference in what i thought i was to do (weakest link in the chain etc.). Plus i didn't want to dive into the factory elects without getting advice from those on this forum.

Based on what you have said, i will run another 6b&s or 8b&s cable along the traxide kit cable from aux battery to the jack compartment in the rear of disco and run it out the hole that i've run my traxide power cable (that may be a tight fit but no doubt some lube will assist) and out to an anderson plug connection to new wiring to run to the camper fridge.

BTW - i have a 'Fridge Switch' in the camper to protect the car battery (aux in this case) from going flat during longer stops.

Hi Rossco, if you do go down the dual cabling road, and this is also what Dometic recommend, run the second cable from the cranking battery, not the auxiliary battery.

The reason is that while the kit you installed has a thick cable running from the cranking battery to the auxiliary battery ( via the SC80-LR ) because of the high CONSTANT current draw of a 3 way fridge, you will still have a problem with increased voltage drop between the cranking battery and the auxiliary and house battery(s), which will mean you need a long drive time to fully charge a low auxiliary battery.

The diagram below will help you and while most people don’t want to set up this way because it is a big job, but the set up you’re planning is the OPTIMUM way to run a 3 way fridge and get the best possible charging for you auxiliary/house batteries.

Hi Tim,

The deeper i dig - the clearer it gets....many thanks for your reply.

Based on the diagram you've provided, i am virtually half way through the 'big job' as you've described it insofar as i have installed the Kit 5 and hence after this weekend, i'll have run good cabling in the Camper and the house batteries will charge from the Disco when driving.

Presuming that i get stuck into the second half of the big job, i imagine that running 6b&s or 8B&S from the cranking battery to the rear of car can be routed along the drivers side of the car in the same fashion/alignment as the cabling already installed?

Getting cabling through the (previously grommit filled) hole in the firewall will be a challenge i expect? Other options for cable routing? i presume that there is a similar hole in firewall on the LHS but access not possible due to location of battery box housing?

Will two sets of 6b&s and the trailer plug wiring fit through the little hole in the firewall and at the back of the panel-work leading through to the trailer plug?

Also, the circuitry shown in your diagram that is connected via 3mm Auto cable - would this be additional or basically existing wiring connected to the Dometic?

Lastly, (yeah right!) I presume that the Fridge Switch terminals is where the connections from 'Connect to Vehicle 12v battery' would go so that the Fridge Switch can perform its intended function of cutting draw from the cranking battery when the vehicle is stationary?

I can see the size of the job emerging before me with most of the work being convincing cables to go through little holes that already are filled with cables but i'll have the car for the next 4 years and cold food and beer are important requirements of a three month long service leave trip so i am prepared to have a crack at it (or get the second cable for the fridge run by the dealer when the car goes in for 13K service after Easter might be preferable...pay someone else to bleed and sweat!).

Hi again Rossco, 8B&S twin is all you need and you pick up the positive on your cranking battery’s pos terminal at the same point the kit picks up.

Shorten the negative back to the driver’s side and pick up the neg at the negative post, again where your kit picked it up.

You need to put a 30 amp auto resetting circuit breaker in the positive cable, and mount it in the driver’s side battery compartment.

Next, you can not get any more cable through the hole you have your 6B&S cable going through but there is another hole, just to the right of the master brake cylinder.

To simplify things, have a look at the link below as it describes how to run the cable through the other hole and under the dash and there’s plenty of pictures to help.

Any problems, post up here or phone me.

Have fun

http://www.aulro.com/afvb/verandah/6...le-kit-d3.html