12 pin trailer plug question

Submitted: Sunday, Sep 06, 2015 at 20:31
ThreadID: 130205 Views:5516 Replies:2 FollowUps:4
This Thread has been Archived
Looking for info on wiring of a 12 pin trailer plug. I am soon picking up a new Jayco Journey & have to wire the 12 pin trailer plug with two 12 volt feeds, One for the caravan fridge & one to supply the ESC & Breakaway.
I currently have a CTEK D250S in the rear of the Pajero fed from the cranking battery. This charges the Fridge battery in the rear of the Pajero which runs my 40 Ltr Engel. It also goes to the Anderson Plug to charge 2 x 100ah batteries in the caravan when driving.
Is the CTEK able to feed these two extra 12 volt supplies for the 12 pin plug as well as the loads it already has? Or do these feeds need to come direct from the cranking battery?
Keeping in mind the CTEK already charges the Pajero Aux battery & the two 100ah batteries in the caravan.
I'm trying to avoid running the wiring for the 12 pin plug back to the cranking battery.
If I tap off the output of the CTEK I am concerned the extra load of the fridge in the caravan & the ESC & breakaway will be too much for it.

Hoping to hear from people who do know what their talking about please.....
Thanks in advance
Back Expand Un-Read 0 Moderator

Reply By: Member - Phil G (SA) - Sunday, Sep 06, 2015 at 21:27

Sunday, Sep 06, 2015 at 21:27
Manufacturers are inconsistent with this.
Jayco should provide you with a wiring diagram to tell you what is connected to each pin. Just went thru this exercise with a New Age caravan.
Pin 8 of the 12 pin plug supplies power to the 3-way fridge (when operating on 12V) and to recharge the small 7Ah breakaway battery. I sourced the power from the aux battery in the Landcruiser.
The grey anderson plug is there just to recharge the caravan battery.
There is a separate red anderson plug to provide power to the ALKO ESC - that comes from the vehicle cranking battery via a 30A circuit breaker. Some manufacturers will skip the red Anderson plug and have the ESC power come thru the 12 pin plug as well.

It is a big ask to expect the D250S to recharge 3 batteries, and power both fridges.
We need more info. Is the caravan fridge a 3-way or compressor? Do you have solar panels on the roof of the caravan?
AnswerID: 590058

Follow Up By: pmk03 - Sunday, Sep 06, 2015 at 21:40

Sunday, Sep 06, 2015 at 21:40
Hi Phil, Thanks for your reply
Jayco have supplied a wiring diagram & I am familiar on how to wire the 12 pin plug.
You answered my question with your second last sentence.. Thanks
I was thinking the same that it was a big ask for the D250S to do it all.
I know it is capable of charging all my batteries & running the engel but as I have a 3 way fridge in the van the current draw on 12 volt will probably push it over it's limit.
Jayco power the ESC trough the 12 pin plug so there is no red anderson plug in my setup.
Thanks for the info
FollowupID: 858048

Follow Up By: Member - Phil G (SA) - Sunday, Sep 06, 2015 at 22:06

Sunday, Sep 06, 2015 at 22:06
Paul, Sounds good.
Our 3-way fridge in the caravan was pulling 13.5Amps continuous when I measured it last week.
Our van has 240Watts of solar which keeps the caravan batteries well topped up as the battery just supplies accessories and not the fridge. So I don't feel the need for a DC-DC charger in the caravan.
FollowupID: 858052

Follow Up By: pmk03 - Sunday, Sep 06, 2015 at 22:14

Sunday, Sep 06, 2015 at 22:14
Geez that much !!
Think I will get a new feed from my cranking battery to supply the fridge & esc with those figures. Was just being a bit lazy & looking for an easy way out as the Ctek is already in the rear of my car.
Forgot to mention I do have a 150w solar panel on the van roof.
Thanks again........ Think I'll just do the job properly & do it once.
FollowupID: 858054

Reply By: Member - Bigred13 - Sunday, Sep 06, 2015 at 21:31

Sunday, Sep 06, 2015 at 21:31
Hi Paul, In your brief above ,you have said that you have a Ctek 250S charging the Van batteries as well as your ute fridge via an Anderson plug ,so I gather you have heavy 6 B&S wire there already ?.The breakaway on the van is fed from the van batteries ,which must be part of the van , so if the van parts company the breakaway will activate the brakes and hold them on for a minimum 15 minutes .I am not familiar with the ESC you are talking about ,so I am not sure what power is needed there .So in my opinion ,the only question is what is the power requirement for the ESC ,as the other items are taken care of it seems .Do you really need a 12 pin ? ,as any heavy loads will not be able to pass through those small terminals anyhow .
AnswerID: 590060

Follow Up By: pmk03 - Sunday, Sep 06, 2015 at 21:47

Sunday, Sep 06, 2015 at 21:47
Hi Bigred13
The 12 pin plug is needed to power the 3 way fridge in the van while driving.
ESC is Stability Control & in my case is also fed through the 12 pin plug.
This is a standard on all jayco vans & probably many others.
Thanks for your input
FollowupID: 858049

Sponsored Links