Land Rover Discovery 4 and 17.56-1 Wiring

jeffa32

New Member
Mar 28, 2012
14
1
0
Hi All,

We have a 17.56-1 with a large fridge and battery pack on order. Our tow vehicle is a Land Rover Discovery 4.

Can anyone provide advice on what wiring is required to power the fridge and charge the battery whilst driving. I already have a red arc brake controller installed.

Just curious on whether the white trailer plug at the back of the vehicle can be used.

Thanks in advance.
 

shadow75

Member
Aug 25, 2011
98
9
8
Sale, Victoria, Australia
Hi there Jeffa,

Are you getting an Anderson Plug additionally installed on your Caravan? typically these are wired directly to the battery.

Typically Jayco use a 12Pin plug for the larger fridge installations. For me the battery in the Caravan is still getting charged without the Anderson Connection via the SETEC, albeit only at a very slow rate ~ 1amp. The Anderson Plug setup charges at a significantly greater rate ~20Amps

By using an Anderson Plug, and separate wiring from the Car Battery, you avoid the voltage drop induced by the fridge which can suck a considerable amount of amps. The advantage there, is that with the lower voltage drop to the Caravan Battery, it will charge to a higher %. That is dependant on your Alternator output..

For me, I ran 2 separate 6B&S cables to the rear. For the Caravan.. Possibly slight overkill, but is working well.

If these in any further question, just ask :)

Cheers, Glenn
 
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Mike7

Member
Nov 10, 2011
144
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18
Hi, I have a disco 4 towing a 16-49-3b and am in the same process of trying to work out what to do. So far this is what I've come up with.

The round 7 pin land rover to 7 pin flat cannot power the fridge, the wires are too thin. I used to have pin 2&3 power the fidge in my previous tug, a Toyota.

It is possible to buy a narva 7 pin round plug (super cheap auto, eBay etc) and wire up an Anderson plug and us the white aux power out ( need to remove centre pin in the narva) in the back of the disco 4, BUT, there's always a but, it depends who you speak to as to what that aux plug can supply. Speaking to LR here in Sydney they are quoting a figure of 40A that can be supplied from that plug, they have said it might also be 30A and I've also been told by another D4 owner that the aux plug is protected by a 10A fuse so that would indicate a max of 10A. Yeah I'm confused too. Also the wiring between the alternator/battery to the back of the plug is an unknown and it has been suggested that it's pretty thin, if anyone knows for sure I would luv any input. Problem here is the voltage drop issue that Glenn has mentioned above.

I'm thinking that Glenn's setup would be ideal, ie separate Anderson Plug the rear of the car to supply the van. The alternator in the D4 is supposed to have quite a high output, 180A max with about 47A at idle would you believe. This is required to make sure all the electronic wizardry still works in the D4 when it's idling at the lights. However this would mean that if a descent cable is fitted between the car and van we should be able to get a descent charge into the van batteries.

I was thinking a single Anderson plug to charge batteries and I'm hoping with some more research I can use the land rover aux power at the rear to power the fridge. If all this doesn't work I'm thinking to power a ctek D250 dual via the Anderson plug to use as a DC-DC charger and also use the same Anderson plug to also power the fridge.

Cheers
Mike
 
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Billrw136

Well-Known Member
Jun 20, 2011
849
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North Rothbury
Hi there - I tow a 16.49-3OB with a Discovery 3 - we have 150l fridge in van. I had a 12 pin plug fitted to LR as well as Anderson plug - the latter runs to van batteries - the former supplies power to fridge when travelling. The factory plug on the left as you look at the car was removed years ago when we were towing a camper trailer (that was when the Anderson plug was fitted). The plug on the right is still active. 12 pin plug had new wiring installed to supply it. I also have second battery in vehicle to supply dedicated outlet in cargo area for Engel fridge.

Cheers

Bill
 
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jeffa32

New Member
Mar 28, 2012
14
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Thanks for the replies.

I have been advised that I need a separate Anderson plug run to the back of the car. I will also get this wired via the ignition so it does drain the battery should we stop for any length of time and have the van connected.

Will this be enough to charge the battery pack as well?
 

ROnEM

Well-Known Member
Mar 13, 2012
650
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Macedon Ranges, Vic
Jeffa,

If you are going with the large fridge, Jayco will typically wire the van with a 12 pin plug. The dealer has already supplied me with the Narva flat 12 pin plug to fit to my car. The fridge will draw power through this plug and the Anderson plug will connect directly to the van battery/s.

My auto electrician (and others above) has said to run 2 x 6B&S cables from your battery to the Anderson plug (to avoid voltage drop) and this can also then cascade from the back of the Anderson plug to the 12 pin plug - pins 9 (heavy duty +ve) and 10 (heavy duty -ve/earth) on the 12 pin plug. Also, if you fit a battery isolator between the car's battery and the 2 x 6B&S Cables to the Anderson Plug/12 Ping Plug, then you will not have any problems with the fridge draining your battery if you stop the car and forget to disconnect the plugs or change the fridge over. This will also make sure that once the car's battery is fully charged at 13.5v, that the van can start charging and will not let the car's battery voltage drop below 12.7v, so you can still start it!

I have also been advised that when fitting the electric brake controller, to also replace the "blue" brake power wire from the controller to the rear of the car with a 6B&S cable so that you get less voltage drop and minimise potential electrical problems in the future.

Cheers,

Ro