Wiring vehicle to camper trailer

Hi Wombat, I would make sure that the wiring on your vehicle is able to carry the current load on the two unused auxiliary pin connections on your trailer plug (if they are going to be used). Some Trailer plug wirings are only light duty just sufficient enough for lights only.
Not knowing the current draw rating on the trickle charger I can only suggest that the wiring is able to carry a load in excess of that required to be on the safe side.
Hope this helps. Cheers.Have Wheels Will Travel

Wombat it should be wired to 50amp anderson plug direct from main battery via circuit breaker as close as possible to battery with min 6mm twin cable but any sparkie worth his salt should know this.Wish i was still here / Gulf in July

Hi Wombat,

Recently been through a similar exercise with our camper. After plenty of research this is what we did. Ran 10mm wire to trailer battery via an anderson plug and 4mm cable through 7 pin plug for electric brakes. Reason we went with anderson plug is it is more reliable, less voltage drop and you really need a large 7 pin plug, not the standard smaller sized 7 pin plug. Also, if for any reason you don't want to be charging the trailer battery, its simply a matter of unplugging the a/plug.

Hope this helps.

:o) MelissaPetrol 4.5L GU Patrol &
Camprite TL8 offroad camper

What has been suggested is all good stuff.

The wire for the brake controller, from the unit to the seven pin plug at the bar, should be as heavy as the plug will take. Whilst light wire will work, the heavy wire will allow the brake magnets to get full voltage.

Also I suggest that you need a battery load sharing device, there are various types, but we used the Pirana electronic one, what it will do is give you car battery for starting, and once the car is started, it will allow charging of the battery in your trailer. The battery in your trailer should be fitted with a low voltage cut out, which will shut off the trailer battery when it get down to 11.6 volts. If this is not fitted, then your battery in the trailer will be quickly destroyed.

The Pirana will also stop you drawing current from the cars battery, when the car is shut down. This system is fully auto, and is better than manual switches and relays.

Regards

Col Tigwell

Hi Wombat,
I have just completed rewiring up my car and caravan.
I have a Trojan deep cycle battery mounted on the draw bar of the caravan. This battery is fed indipendantly via an Anderson 5o amp plug. Not not try and run these cables through a normal 7 pin plug be it the large or small size as they are not capable of carrying sufficiant current.
Do not use anything smaller than 10mm cable and take both the line and the return back to the vehicle battery. You will need a good quality circuit breaker installed on the posotive cable in the engine bay.
Using this method I am getting 13.7volts at the secondary battery.
I would also suggest that you put an isolating switch on the posotive cable as it exits the secondary battery as caravan manufacturers are not too generous with earth cables and spurfy currents are not too uncommon.

Hi wombat,
Will join the chorus of people giving advice which will probably make you even more confused than you were! I have an Aussie Swag camper which has large battery and battery management device built in. It also has an Explorer fridge on the drawbar. The fridge supply can come from one of two sources - the vehicle or the trailer - and so there are two anderson plugs (one above the other) on the trailer. When I'm driving, it makes little sense to have the fridge drawing power from the trailer battery, and the car charging the trailer battery, so the idea is that you plug into the vehicle supply. When unhitched or stationary for a while, you don't want to drain your vehicle batteries unduly, so you swap to the trailer supply. I am getting to the point.......
On the vehicle, therefore, the Aussie Swag solution is to make use of the two vacant wires, one for trailer electric brakes, and the other for powering the fridge while driving. Provided you use 6mm wire to a large round plug for the fridge supply, I can't see a problem. In my truck, that supply comes from the second battery, which disconnects from the main battery when the key is turned off. The main charging wires come from the main battery, and these are big suckers - forget the name, but the core is 6 mm or so in diameter (as opposed to what some people call 6mm, which is more like 6 sq mm). These run to a separate anderson plug, and on the trailer side run directly back to the battery management device. So I have two plugs from vehicle to trailer. I don't have any fancy electronic management/isolator devices for the charging wires, and haven't had any problems, but fill your boots!
Just quickly on the brake controller front, you might consider a Prodigy proportional brake controller instead of the pendulum device. They are all electronic, which gives flexibility in mounting, and they are VERY good. Cost a bit though....

Enough rambling. Enjoy your trailer!

Russell S.Russell S
Prado RV6

Hi Wombat I know you are having your trailer wired but thought I would add this anyway, recently I bought a Waeco Thumper battery {around $650} to add to one of our trailers as this allowed me to make it portable and ended up ringing Waeco to discuss this very problem and as it turns out they actually make and sell a kit that supplies power from your car battery all the way through to your trailer, it boasts true 6mm cable 50amp anderson plugs at the tow bar, it has a isolation switch at the car battery end with a wire that is connected to an ignition switch so that it {if you set it this way or can be bypassed} only allows power to flow to the trailer when the car is running, it has extra twin wires from the car anderson plug to allow another power source to be added to the back of your vehicle, it has the special connection trailer end for the Thumper battery but they may be able to delete that from the pack and also extra wires at the trailer end for another power source.
It all comes in a pack complete with cable ties and directions, there are a couple of tricky bits, ie:finding the ignition wire to attatch to but all in all it was very impressive, cost around $150 I think but there isnt anything else to buy and from what I can find out it doesnt allow power to flow backwards back to the car.
I am still in the middle of installing so will let you know how it ends up.

Chris
Karratha

Thanks everyone for the advice and tips. I think I've got my head around what I need to specify. Now I just have to convince the auto electrician that I "really do" know what I want!Live today as if there may be no tomorrow