jayco camper[hawk] trailer inverter/charger?

thanks for the tip! i thought that i might find a electrician out there on the forum net i know its possible as we are only dealing with small watts except for the 240 volt inlet , i was only concerned about back feeding the battery directly off the 240 hence the regulator etc.
also does anyone have a diagram for the electrical circuit for jaycos as they dont supply any with the paperwork when you purchase it

i think that you can't get zapped with 12volts!, in the camper the inverter [aka transformer] is supplied by 240v, it then reduces this down to 12v to supply lights fridge etc , if a supply line is delivered to the battery it is feeding at 12volts just like the lights etc, if i supply a regulator in line this will cut supply to the battery when it is fully charged ,correct?
when not on mains i can supply the camper thru the transformer at 12 volts to the appliances from the battery, all i need is a one way feed switch to prevent the 240 supply back feeding the battery, correct? it seems pretty straight forward question? if you dont know the answer then dont respond thanks ,i dont need a lecture on safety just a educated answer, i was going to get a sparkie anyhow ,i was just wondering abut the probility thanks

YES! thank you very much hughesy, i thought i was on the right track as every thing comes off the transformer as 12v, i'll check the total load on the transformer and change to a charger
what do you do when your not on 240 and just drawing off your 12v system or does it automatic flow through the charger
do you have any photos or a diagram to follow as most jaycos are the same set out
does the fan on the fridge make it perfrom better as mine is great on gas but doesnt do wellon 240 or 12v was thinking of the boost fan like yours to increase the flow of hot air out of behind the unit
thanks

Sorry I'm a bit lost mate with your description ie. transformer and auto flow thru charger??

When I have 240v plugged into side of the van (at CP) this powers all the 240v outlets in the van which in turn powers my battery charger that then keeps the battery topped up. All the lights and other accessories just run straight off the battery similar to what you would have in your 4x4.

I have no 240v available if not connected to mains...ie no inverter mainly because those appliances would only drain the battery to quick anyway.

I'm pretty computer hopeless mate (ie posting pics) but if you email your mobile number I'll try and take some snaps with my phone and send them on and you can give me ring then if you like too.

I'm spewing I never took any photos of what the wiring looked like before I changed it all so you could see the difference.

Anyway give me a bell at: jason_hzj75 at hotmail dot com

hughesy thanks for the update i know no your method off madness ,quite beautifully simple and effective ,sometimes it just takes one more brain to over come a problem my industrail arts teacher freind and me have nutted it out!
quite simply your saying that the system works like this 240 to charger then 12v from charger to battery and everything feeds of battery, correct? hence when your on 240 there is no problem as evertyhing is feeding all ''downstream'' so no ill effect on battery as its just charging it up fantastic!!
how well does your fridge fan work?
is your pump off the water tank flow activated or do you just flick as swtch
ill email you soon a bit busy today as cleaning the house as my brother and family are coming to visit and they dont like dust
thanks again for your help

Yep you've got it now ;))

I've actually got 4 fans on my fridge. I experimented with just one initially (as that was all I had) but for it to work effectively (ie. no air short circuiting) you have to block off all of the vent that you have fitted the fan too. This is fine while you have the fan operating but you don't need the fan at night or in the cooler months so you would have to remove the "blind" continually.

So I just bought 5 computer fans 2nd hand off ebay for $15 and mounted 3 across the bottom vent (sucking in to the van) and 1 at the top (pushing air out). Just zipped tied the fans to the vent grill.

I've been too lazy to actually put a switch in for the fans (too noisey to run at night) and just turn them on and off by pulling the fuse from the distribution board I installed. Some people have put in temp sensors behind the fridge to turn the fans on and off automatically - but if they started during the night it would wake me so I haven't bothered.

They certainly make a difference as I have mounted one of them little inside/outside thermometers next to the frdige so I have an idea what temp its at and after a 1/2 day driving and then setting up it used to take till 4am before the fridge droped back to about 4deg C (from about 11deg C) This is summer and far west NSW but with the fans it would cool down by 10-11pm. I feel the temp of the bench above the fridge as a guide to how hard the fridge is working and whether I'm getting the heat away sufficiently.

A little tip - ALWAYS have the fridge powered on 240V for about 48hrs before you head off, adding the food to it 24hrs before so that it is at temp before leaving. They take for ever to cool down the first time (well in summer anyway). They at best only hold their temp on 12v (ie when driving). If anything expect the fridge to have warmed up a little while driving. The freezer stays cold its the fridge compartement that warms quickly. Strongly recommend a digital thermometer.

As for the water pump - I don't know what year your camper is but I had a 2-way (Lowboy) hand pump which you could pump the water from the tank or push the handle down to get mains pressure thru. I bent/broke ours once when I pushed bed end in and hadn't turned the sprout around. While looking at a caravan parts place on the WWW I found the same model tap but 3-way (about $65 I think). It was the same as the existing one but if you lift the handle up to the highest position it activated a switch in the unit.........easy peesy just hook some power to this and onto the inline Whale pump and you have pump water in the sink.

Running the power to the new tap and installing the pump probably took me about 2hrs. I mounted my pump to the floor of the camper and you only have to hand prime it the first time you use it or after tank has been drained (ie use hand pump) and it stays primed after that. If you mount yours to the floor put some thin rubber or something between pump and the floor as the noise of the pump (vibration) seems to be amplified by the timber floor of the camper.

I'll put the camper semi up today and take some photos for you.

thanks for the great tips and actual notes on the installation process clearly understood, you should get a job with popular mechanics!, i wish that there is more of you out there, as its great to get this stuff that i can use and dowithout getting in a bother and twist.
thanks
m.r.m.w
love your work

I took those photos of what I've done and even put them into a word doc with some explaination of whats been done. Send me an email and I'll forward on mate.

the kids have done something to the email out box cant seem to send mail heres my address cto29694@bigpond.net.au

peter d , thank you for your informative and concise information its good that this site can be used to distribute useful information so others can modify their campers and equipment without having to spend lots of money on ''pros'' when we can do it ourselves with a little help form people like yourself
the money saved can be spent on taking our loved ones to great places in this great country
thanks
love your work
m.r.m.w