Electrical 12 pin to Anderson

[andrewghamilton]

Hi

I just bought an expanda with a 12 pin plug and changed to a 7 pin pin flat plug with two wires left over that are the heavy gauge you would use to charge the battery (which is what they did for the previous owner).

I don't want to upgrade my car to a 12 pin plug so I'm thinking I can probably just connect the two thick cables to an Anderson plug and charge my battery directly from it.

Is there any danger with doing this?

As far as I can see its just changing the way the power is inputted.

 

[dagree]

Shouldn't be an issue @andrewghamilton if you already have an anderson plug wired on the car.
Also make sure it is fused!

 

[Glen Bundesen]

Yes, but just be careful that you have the positive on the car going to the positive on the caravan going to the van battery. Also negative to negative!.
On our Coromal the heavy wire is for the fridge - so it powers it while driving.

 

[chartrock]

Like @Glen Bundesen says, make sure the two heavy wires left over are for the battery and not for the fridge. If they are for the fridge you may flatten your car battery if left connected with the car stopped.

 

[andrewghamilton]

yeah cheers for that. I will trace them and see where they head.

I put the multi on the wires from the caravan today and got nothing at all in terms of volts. I would have thought that if it were connected to the battery I would have got 12v from a fully charged battery.

So maybe they do go to the fridge.

I checked the wiring on the standard 12 pin plug and it does show red as battery and white as earth

 

[dagree]

Good Luck following jayco's wiring
It does sound as though it's a feed for the fridge. Our expanda came wired with them to feed the fridge and charge the battery so anything is possible?

 

[Glen Bundesen]

If you find they are going to the fridge, I'd suggest you investigate if the car has a device on that heavy wire circuit to check for voltage drop below ~ 12v Forget what they call them but it stops the fridge from draining the car battery, It happened to me - we stopped at a musuem about the Flying Doctor and spent longer there than anticipated and yep the car battery was flat. Couldn't unlock the car with the remote - great fun!

 

[dagree]

There are 2 different types
Low Voltage Cutoff switch Same as I have setup on our van and has 3 voltage cut off settings

Or
Motion Sensing Fridge Switch

The best option is an ignition powered relay setup so fridge won't run unless the ignition is on!

 

[pauljygrant]

What are the remaining colours in the 7 pin plug? Is there a black wire that might be used for battery charging?

 

[Doc]

I use a 7-pin plus heavy 2-pin (not Anderson, I use a different neater type). The dealer is changing my new Jayco from factory-fitted 12-pin, to my setup prior to delivery.

When you wire your vehicle, DEFINITELY ensure that the wiring feeding the 2-pin socket is switched and protected. For protection, you can either use a circuit breaker or a fuse - up to you. I prefer circuit breakers for these types of circuits (~50A) as large fuses can be problematic to source spares. As for switching, the circuit should be switched so that it is either ignition-switched (via relay), or via the charge level of the vehicle battery (eg voltage sensing relay - VSR). Personally, I use a VSR to switch the circuit, and it basically behaves just like a dual battery system would. I prefer VSR over ignition-switched, as the circuit is then being switched by the actual charge state of the vehicle battery, not arbitrarily based on the position of the ignition switch.

In many vans, the two heavy-gauge wires feed the battery VIA A RELAY. The relay switches the circuit when ignition-sourced power is supplied by the spare circuit in the 7-pin plug. Pin number 2 (black - labelled as 'reversing lights') is commonly used as an ignition-switched power source. It is important that your vehicle be wired to only provide power to that circuit when ignition is on or engine is running. When power is applied to that circuit, the relay allows power to flow from the Anderson plug to the battery. When power is removed, that circuit is deactivated.

Now, this is general principle stuff. I am not certain how the system works on Jayco as I haven't investigated it, but would be surprised if its substantially different.

Bit of a ramble, but I hope it helps.

 

[boots33]

yeah cheers for that. I will trace them and see where they head.

I put the multi on the wires from the caravan today and got nothing at all in terms of volts. I would have thought that if it were connected to the battery I would have got 12v from a fully charged battery.

So maybe they do go to the fridge.

I checked the wiring on the standard 12 pin plug and it does show red as battery and white as earth

If the wire goes to your battery via the setec (most common jayco setup) then you will not get any voltage back to the plug as the setec has a blocking diode to prevent this. you will need to trace the wires to make sure where they go

 

[Chaser]

I found recently on my van that pin 2 in the 7 pin plug feeds the battery and the breakaway system battery in the van and pin 9 positive and 10 negative are for the fridge that you should put on the anderson plug.

Cheers
Chaser

 

[kozza]

I found recently on my van that pin 2 in the 7 pin plug feeds the battery and the breakaway system battery in the van and pin 9 positive and 10 negative are for the fridge that you should put on the anderson plug.

Cheers
Chaser

I was told the same by Jayco Dealer

 

[Drover]

A common Jayco practice is for the heavy wires from the plug (whatever type) they usually are black +, white - and they will run to a shoddy cluster of joins at the end of drawbar before heading into the van, now this heavy pair can turn into 2 cable runs in this cluster, one will run to the fridge and the other will run to the battery but via the Setec which has a diode to stop the battery being drained by the fridge, thusly you shouldn't get a reading on your meter ........now this isn't all that bad an idea as you can run the fridge and charge the battery when plugged into the tug,(battery switch needs to be on) the join at the cluster usually needs a revamp as it's shoddy, fitting a fridge switch is easy plug and play once you pull the lower fridge vent off and is really a necessity.......see my 14ft page for my cheap mod......
Using an Anderson for fridge/battery charge will mean once you set it up you won't have to bother with it again, (7 pin will plug into 12 pin) besides 7 pins are cheaper but you can use 12 pins don't use the large pins as they are the ones that cause the problems with heavy currents, they melt as the pins wear/compact etc...................Solar chargers my battery and the breakaway is charged from the tug but that may change soon.