24 Volt 4WD

Get a Waeco or Engal fridge that will run of 24VDC. It'll be heaps more efficiant.
Buy 24 - 12v power supplies from Jaycar for the other equipment.

My Humvee is 24v (after having 6 12v toyota's) and I reckon 24v is heaps better especially starting, half the current flow too.
What you need is a Redarc charge equaliser, as you stated it equalises the chareg level of the batteries. You can draw 12v from either or both and it will float both batteries at the same potential (voltage/charge level).
I've had one on the Humvee since I got the truck (now nearly 3 years) with absolutely zero probs. My Autofridge is 12 or 24v (most late model frig's using Danfoss compressors are) and I run it on 24v, it pulls just over one amp.
all the other accessories run from 12v, currently they are: Barrett HF, GPS, Stereo, CB x 2, air compressor, camping lights x 2, AA battery charger, 300 watt inverter, CDMA phone and anything else that can be plugged in walkmans etc.
Wouldn't advise using a12v winch though ;-))
I've changed the camper taillight globes to 24v.
If you need 12v in the camper run a seperate feed via an Andersen plug or similar.
24 to 12v transformers are very inefficient and are old hat these days.

check your ACC circult it should be 12 volt.
the lighting, main , power are 24 but your ACC should be 12 check it with a multimeter. the jap GQ are nearly the same as the AUS MQ wireing.

as for blaised when drawing from a battery with an 12 volt circult dont worry about it as the batteries automaticly re balance them selves when the ignition is turned on.

if the jap inverter is to small for the load and truck supplier can fit a larger one for about $80 .

shadow

BamBam.
It is very easy to change the heating element in the fridge to 24volt. if chescold can not supply an element any heating element manifacturer can make one to your sample. Eric.

Hi Bambam
I had a 24v patrol, you will find a 12v circuit in the accersories, I branched everything from that curcuit. I also ran a seperate curcuit from 1 battery for the fridge. Dont let one battery go down a little cause the partol will need the full 24v to start.

good luck mate

Crazie