wiring for a 12 pin connection for 150L fridge

[relgate]

Hi Guys
I've had a look through and can't seem to find a thread about this. Please forgive me if it's already there.

As I will be picking up my 17 foot from interstate in the next couple of months I am keen to get the tug all wired up correctly.
The Van is coming with a 12pin connection as per Jayco's 'recomendation' and I am happy with that.
I have solar so I'm not too worried about charging the van battery from the car, so I'm not sure I see the need to upgrade that side of things. As it stands it will charge via the hotwire (pin2) on the 12pin. Any comments about this welcome.
My question is more about the fridge. I will be getting a 150L and from what I can tell it will be on pins 9 and 10 (+ve and -ve) with a thicker (6mm?) wire. What I would like to know is how the tug is wired in this case. Ie, is there a direct line from the battery to these pins/will the Auto elect just run a thick guage wire from terminals to pins? I assume a fuse will be involved, but is there anything else?

Also, what about the issue of the tug battery going flat when you stop for lunch and leave it connected? I've read threads about this but cant seem to find them. Did someone say they installed some kind of relay? I noticed RV electronics have a device for this called Fridgeswitch http://www.rvelectronics.com.au/page.asp?parentid=3&parent2id=14

Any help is greatly appreciated!

 

[acmackie]

Hi Relgate
I asked local Auto Elec about this just a few weeks back. He plans to run hot wire for the battery, and second for the fridge. He wants to put a solenoid for each hotwire so no issue with draining the car battery when stopped. I also believe in NSW we need Breakaway system Monitor in the tug (to ensure the breakaway system battery is charged enough to do its job), so might be best to get that done at the same time. My van will have VIC rego so I should get away without, but will put it in to be on the safe side. Anyway quote from auto elec for me was about $400+ labour. Since my car battery is about $700 fitted I'm not going to risk killing it by saving money on the solenoids ($300).

 

[relgate]

Hi Relgate
I asked local Auto Elec about this just a few weeks back. He plans to run hot wire for the battery, and second for the fridge. He wants to put a solenoid for each hotwire so no issue with draining the car battery when stopped. I also believe in NSW we need Breakaway system Monitor in the tug (to ensure the breakaway system battery is charged enough to do its job), so might be best to get that done at the same time. My van will have VIC rego so I should get away without, but will put it in to be on the safe side. Anyway quote from auto elec for me was about $400+ labour. Since my car battery is about $700 fitted I'm not going to risk killing it by saving money on the solenoids ($300).

Sounds like you are on the money. I'm not sure how the solenoids work in this case though. what do they do exactly?
I have spoken to 2 Auto elecs and neither seemed to know anything about it! They just want their $$$ to install a cheap brake unit and that's it!
Where abouts in Sydney are you? Where is the Auto elec?

 

[acmackie]

I'm out near Penrith. My basic understanding is the solenoids just isolate the hot wires so they are only active when the ignition is on. Wish I knew more then I'd try wiring it myself.

 

[MolongMick]

I'm out near Penrith. My basic understanding is the solenoids just isolate the hot wires so they are only active when the ignition is on. Wish I knew more then I'd try wiring it myself.

You're pretty much right there. The 'smart solenoids' will only allow battery power to run when the battery is at a certain charge level, once it falls below this, the connection is cut. Once the engine is tarted and battery charges again the charge will be allowed through once more. This ensures there is always enough juice to start the car. I my opinion a very smart move to have them installed. I run two, one for the battery and one for the fridge.
Hope this helps

 

[Burnsy]

Hi relgate,

I'll be doing the same soon myself. If you already have a 7 pin plug with a hotwire and it's at least 6mm then change the plug to a 12 pin and the wires stay the same for the bottom 7 pins and I'll just be looping the hotwire plus the negative the the pins above, not sure what the numbers are. If you don't have a plug or hotwire then I would run a 6mm to the bottom seven pins of the 12 pin plug and then still loop it to the top pins if this makes sense. As for stopping the battery going flat when stopped a relay is all that's needed between the battery and hotwire which also connects in with your ignition, shouldn't cost too much. When we got contract in the mail all the trailer plug info was in there.
Hope this helps.

Cheers.

 

[ROnEM]

Relgate:

My auto elec has done this stuff for years on cars and trucks and based on his recommendations I have done following for our 17.56-2 OB with 150lt fridge.

Battery -> 50amp self reset fuse -> "Smart" solenoid -> two sets of 6mm B&S cable to Anderson Plug -> loop to pins 9 & 10 on 12 pin plug.

The dual 6B&S cable is to make sure their is minimal voltage drop off between the car battery and van, and if for some reason one gets cut by a stone or something else, you still have power to van.

Also have run 6B&S from brake controller to elec brake pin on 12 pin plug. Again this is advise from auto elec who says that brakes are too important to go wrong and the small blue elec brake cable provided by manufactures may be alright initially, but over time you might get voltage drop off that then effects your braking on the van.

He also recommends putting in a 6B&S common earth from the car chassis to the earth pin on the plug and again from the earth pin on the van side to the van chassis. He has spent many hours trouble shooting car/van/float & truck elec problems and most often they come down to a bad earth, or not heavy duty earth cables.

Hope this helps.

 

[Burnsy]

Oh yeah, I forgot to mention as ROnEM said a fuse or circuit breaker from battery to hotwire before the relay. Charging from the trailer plug is not very effective, that's where you need the heavier cable (6 b&s) and is normally done through an Anderson plug. In any case relgate speak to your auto elec about what your doing and what you need and I'm sure he'll steer you in the right direction.

Cheers.

 

[Big Gee]

This is a diagram Jayco Canberra give me to wire up my Prado before we picked up our 17 footer,

I agree with the need for a solenoid or Fridge Switch.

 

[Bank of Dad]

Relgate - sent you a PM on this.

 

[Pieter]

12 pin flat plug & socket
1 left hand turn - yellow
2 reverse - black
3 earth - white
4 right hand turn - green
5 electric brakes - blue
6 stop - red
7 tail, clearance, side markers - brown
8 battery supply - orange
9 auxiliaries - pink
10 earth - white
11 rear fog lamp - grey
12 auxiliaries - violet

​

 

[expanda]

http://www.expandasdownunder.com/sh...r-12-Volt-Fridge-Hotwire-12-Volt-Hotwire-DIYI

I did a write up on this a while back ....

It needs finishing, I am about to do it again in the new car so will polish it up and maybe sticky it.

The only thing its missing is the ignition trigger wire on the relay diagram!

Some clarity -

1) Smart Solenoid - This is just a relay with some intelligence, such as keeping power running to either the fridge or battery until your battery reaches a set voltage and then it cuts power etc. This might be good if you want to keep things going whilst you stop for a short period and let the solenoid decide when enough is enough but running a 150l fridge and charging the battery it will be turning of quite quickly.

2) Relay - This is the same as above but just no smarts in it and is wired to your ignition source so as soon as the car goes of the power to the fridge and battery is cut.My preference for the hot wires is just a relay for both, on and off as the car goes on and off.

The fridge will stay cool for a period of time if not opened and closed anyway once its cooled down.Charging the battery is a whole other kettle of fish, it really comes down to how flat the battery is in the van.If the battery is dead flat then even charging of anderson or 12 pin plug does not work.

If it has half flat then it will take a fair bit of driving around to get it to full charge and more than most likely a couple of hour trip is not really going to do anything.

For me, keep it simple by shutting the power down when the car goes off.No risk on a solenoid stuffing up and flattening the battery and being stuck.

But it really depends on one thing, and that is you!!! Its what sort of travel you do and how much reliance you are going to have on being of the beaten path and if you have 15 amp inlet at your house or not.

If you are just driving to a caravan park 2 hours away and then plugging in and driving home and plugging in its not really a big deal and does not require smart solenoids, anderson plugs etc.

But if you are going to be driving 600k's a day, sleeping on the side of the road etc and using solar etc then it may pay to look at a dual battery setup and a smart solenoid setup.Sorry to add confusion but I have done this in a couple of cars myself now and in the end based on my style of caravaning I just have the relays.

In terms of wire, I am not going there !!!

 

[cancan]

As we are retaining the camper trailer I am having the Starcraft wired to a 7 pin flat with the fridge running off an Anderson plug...same as the CT so no stuffing about if we tow either.

 

[achjimmy]

I recently changed the van wiring and wired the Pajero. On our few trips away the 150 litre did not stay sufficiently cold enough to stop ice cream melting during a day’s travel. That was with jaycos 6mm (auto wire) to the Pajeros very thin hotwire.

The problem with sharing the 12 volt to the fridge and van battery duties is the van batteries will struggle to charge fast due to the high current draw. I ran one run of 6 b&s from the Pajeros start battery to an Anderson on the towbar. It went through a Sensadrive/BEP smart relay (VSR) used because HD relays are expensive and I did not want to go breaking into the Pajeros loom anywhere to drive it. The Sensadrive/BEP VSR was $75 and required no further signal. Cuts out almost immediately the engine is off and van fridge is on. I then rewired the van with 6 b&s and an Anderson plug right through to the van fridge. The result on the last trip is the ice cream is too hard to use!! The option to break the 6 b&s into two pins on the 12 pin plug was too hard for me to bother and having had my share of hassles with trailer plugs over the years I wanted the minimum going through it. I then ran another 6 b&s from aux Pajero battery to Van batteries and another Anderson plug. Bit busy at the back but all tuck up away and easy to hitch up.

I do like ROnEM’s idea of upgrading the brake current wire as well. Maybe next time I have the car apart.

 

[achjimmy]

As we are retaining the camper trailer I am having the Starcraft wired to a 7 pin flat with the fridge running off an Anderson plug...same as the CT so no stuffing about if we tow either.

how lucky are you would love a camper trailer too, might save wear and tear on the expanda, problem i have is the camper trailer i want is the T Van :-(

 

[achjimmy]

Indication of the sectional differecne between 6mm Auto (4.5mm2?) and 6 b&s (13mm2)

 

[Burnsy]

Yep it's like chalk and cheese, I found that out the hard way!

 

[relgate]

Thanks for all the info guys. Lots to digest.
Not sure I need to have a serious charging wire for the battery as I have solar and I am assuming it will do a pretty good job at keeping it charged. Does this sound fair?
Also, as Expanda posed the question, most of our camping will be caravan park with more adventurous free camping coming down the track. Weekends here and there. In a couple of years we will aim for the round oz trip, but might have a different tug by then,

 

[achjimmy]

Thanks for all the info guys. Lots to digest.
Not sure I need to have a serious charging wire for the battery as I have solar and I am assuming it will do a pretty good job at keeping it charged. Does this sound fair?
Also, as Expanda posed the question, most of our camping will be caravan park with more adventurous free camping coming down the track. Weekends here and there. In a couple of years we will aim for the round oz trip, but might have a different tug by then,

I don't know about the solar as I haven't had it long enough either, but ours is only 90watts so I guess it will never charge as fast as the car can charge it, but then if your stayin in CP no worries, good luck with it.

 

[boots33]

Thanks for all the info guys. Lots to digest.
Not sure I need to have a serious charging wire for the battery as I have solar and I am assuming it will do a pretty good job at keeping it charged. Does this sound fair?
Also, as Expanda posed the question, most of our camping will be caravan park with more adventurous free camping coming down the track. Weekends here and there. In a couple of years we will aim for the round oz trip, but might have a different tug by then,

Hey relgate
We have a similar setup with our Tug, a twin run of 6mm for fridge and power (plus the earths as well, so four wires all up) and a 6mm for the brakes as well. There can be no doubt that 6b&s and anderson plugs are the ultimate way to go and highly desirable if you are going to do the round oz trip. but for the moment your requirements seem fairly similar to ours, We spend most of our time off grid with the occasional trip to van parks etc. most of our trips are usually within 6-7 hours from home and we always start out with a fully charged battery and use a 120w panel to keep it that way when setup. The panel has never failed to keep up with our power requirements and on a sunny day has the battery charged up well before lunch. If you are going for longer trips you may experience the problems of fridge not keeping cool enough as listed above, although to date we have had no such problems. take a look at the pic below taken from the 150ltr fridge manual



You can see they only recommend a maximum run of 8m using 6mm wire and most setups will be very close to the limit. Provided you are not a huge power user i think you will be fine.