Electrical Trying to understand wiring.

[Jaybird]

Can someone explain how this wiring may work on my Discovery.
At the time of buying in 2012 I asked for a seperate anderson plug on the drawbar for the fridge. When I put a multimetre on the plug I get the battery voltage, when I put the multimetre on the terminal on the back of the fridge I also get the battery voltage reading the same as at the plug. On the purchase documents I got at purchase it was listed as "Anderson Plug wires running from A-Frame to battery" so does this mean that the anderson plug when attached to the car is receiving power to charge the battery as well as run the fridge. Thanks.

 

[Drover]

What I think they have done is plumbed your 12v circuit from 12pin into the Anderson, this would allow the anderson to power the van battery and run the fridge, depending where/ how they tapped in could mean your fridge may draw from van battery......... I would track the cabling and see, the cable at the anderson should be identical to that at the fridge or fridge switch, if done correctly they should be black and red if any other colour they have probably just tapped into the original wiring........
I would run some cabling 8 B&S to the fridge from tug using the andrson, I have an anderson at the fridge as I need to reduce the cable size to fit the connector as my cable is 6 B&S way to big............ I would then keep the 12 power from tug to 7/12 pin for battery charging whilst on the road if you need it.
The anderson on draw bar when uncoupled from tug should be dead, along with the fridge end other than the light 12v wire for the circuit board if you have an auto fridge....

 

[Jaybird]

Thanks, The anderson on the drawbar is live when unpluged and that wire is red and black where as the wire at the fridge is is yellow and black. Hard to tell where the wire from the drawbar goes as it disappears into the cupboards and there is a false floor under the fridge so not sure how it gets there I wil have to look further. Fridge is not auto.

 

[Jaybird]

After further investigation. The red and black cable from the drawbar enter a pile of wires under the van behind a protective metal shield where it is joined to the yellow and black cable that is the same as that going to the fridge. In reading the manual that I found the fridge must be connected to the van battery as the DC instruction states not to leave it on the battery setting while not connected to the car. This fits with Drovers description of how it all works.The fridge is the 90ltr Dometic so I presume they must all be wired the same in Jaycos.

 

[Drover]

Thought as much so that just tapped in where the wiring from the 12/7 pin feeds, I woud just run a dedicated feed direct to fridge, disconnect and tape up the original cable, that will give a direct feed to fridge..... Check that the 12v feed in the 12/7 pin plug is still active, that will supply the 12v from tug to your van battery, if its not active have a look in the birds nest they may have cut it there or more than likely just isolated the wire in the 12/7 pin but if you have a good solar set up its not really needed.
With a dedicated feed to fridge or any for that matter fit a relay/fridge switch which will cut the power to fridge when you stop as they can draw down your tug battery very quickly, enough to loose crank power anyway oryou remember to unplug each time you stop for smoko................. on my 14.44 I just fitted a standard relay that was taped into the side lights, that way when I stopped the tug would chime away because I had lights left on, turn off lights fridge shut down, just have to remember to turn the damn things on again......lol.........