12V & 24V wiring set up

[shesgotthelook]

Veronica my 1962 Viscount has switches & globes for both 240V & 12 or maybe 24V. The internal lights will not run off the car. All wiring on plugs appears present & correct. I cannot find anywhere in van for a battery. There are some wires coming in under one of the beds, black ones are continuous but 2 white ones are cut & taped over. Could they be wires for a battery to run the lights?

[akeepsake]

SGTL reckon it's 12v Sometimes a 12v supply was taken straight from the tow car and was connected via 3 pin socket on the draw bar . These were the same as a round 240v socket . It may have been removed and the wires may still be under the front of the van near one side of the frame where the drawbar connects
If not it would be easy to parallel a positive wire from one of these lights and I suspect the negative may be earthed so off the frame would do. Just grab someone who is handy with a multi meter and should be a sinch ! Just make sure the wires aren't 240 v supply!! When in doubt grab an auto elect!
Hope that helps

[Franklin1]

G'day sgtl,

I'm thinking your van would most likely be 12V globes, to match the 12V car batteries from that time period. Might be time to get your mad scientist white coat on, and do a bit of exploration with the wiring. For goodness sake don't have the 240V plugged in when you're doing any testing - you just never know what some weekend warrior might have connected up in the past.

I use one of those 6V torch batteries to check caravan 12V wiring. You know the batteries that have a square body, with two copper spiral terminals on the top? Used in the old Dolphin torch lanterns, they were. Cost about $3 in the discount stores for a cheapy brand. They will light up a 12V globe enough to know that it's working. I just connect wires from the torch battery terminals to other 12V wires to see what lights up and what doesn't. Obviously, you have to know the existing globes are all in ok condition.

You can do the same job with a multimeter, if you're savvy about using that sort of equipment (and have one). Set the multimeter to the "continuity setting" and test the wires to see if you get a reading. It's a good way of working out which wires are joined to which.

I gather the cable from the tow plug just disappears up into the wall cavity of the van, and not into the seat box? Pain in the butt when they do that. It means you have to dismantle the tow plug and shove the end of the cable in to the van somehow. Then you can work inside the van doing your tests, and all wiring is within reach.

If you find those stray wires under the bed are actually the feed wires for the lights, you could re-route them back to the tow plug so the car operates the lights instead.

Good luck with it.
cheers,
Al.

Edit: Oops, here I am typing at the same time akeepsake is posting. Ignore any duplicate stuff in my post, sgtl.

[greedy53]

if you have a battery laying around try conecting the black to neg and the white to pos. as for wired from the car some people use the blue electric break in the cars plug and the same with the vans plug

[Rattles]

If The van has a 6 pin Plug then the pin 5 (Electric Brakes) (my 1965 Ambassador used this pin) most likely used to connect car battery to the 12v (Black Switches) lights, if the connector is a 7 pin most likely the pin 2 (Reverse), pin 2 was still in my 2000 Millard.

Rattles

PS shesgotthelook where do you hang your hat, most likely a forum member close may be able to help.

[shesgotthelook]

Thanks everyone, we do have a multimeter. Will get Mr SGTL to read all this & see if he can sort it out himself. Rattles, I am at Rochester near Echuca in Vic.
To me it looks like they would have run off the car, but why the don't work now will take some lengthy investigation.

[Rattles]

This may Help This is the Old way of wiring a 7 pin Plug, for other connectors and the current 7 pin plug allocations see this link:
www.campertrailers.org/trailer_wiring_diagram.htm

Rattles

[shesgotthelook]

All the wires are white Rattles We have given up on the Viscount & dropped her round to an auto elec's house today. So, turn our attention to the GlobeTrotter which I've never been able to get the 12v going in either.
I was sure it had clamps for a battery but must be developing altzheimers. All it has is a 3 pin plug under the seat. When touch wires from battery to this plug, the lights work!
Now before we go cutting this plug off & putting on battery clamps, what would it have plugged into originally & is there some sort of adapter?

[pothole]

The Millard that I got some bits off originally had a setup under the front seat, three pin plug into fixed [ screwed to floor ] 3 pin socket. short lead to battery.

[Rattles]

shesgotthelook - Connecting to the battery using the wires on the plug will light the 12v lights as you have indicated however the battery will not be charged without connection to the tugs battery and or to solar/genny, however if battery is only required for free camping and not for more than a couple of days, The tugs battery will be sufficient for overnight stays with a direct connection to the tugs cranking battery (all my previous caravans have been wired this way and my current 2000 Millard with 12v Lighting has a changeover switch from tug to house 12v supply)or if fitted the tugs auxiliary battery.
Of course if running a 12v element in a 3 way fridge then this needs to be switched from tugs ignition or fridge switch.

Hope this helps and not muddy the waters.

Rattles

[mibosa]

I am in the process of doing up my 1966 Viscount Ambassador and am installing a 130AH deep cycle battery to power the 12v spotlights, 12v strip lights and 12 volt power sockets. Whilst travelling to a location, is it the idea to have the 12v power going from the towing vehicle directly to the three way fridge or to the battery and have the fridge running off the battery and upon arrival and setting up to then flick a switch to stop the battery powering the fridge whilst using 240v or gas? The wiring required for the 12v lighting etc is only small but I see that the wiring to the back of the fridge is thicker. I have noted the chart and advice from the above forum members so any further advice would be helpful. I may not respond quickly due to some overseas travel. Regards, Bob.

[Geoff & Jude]

hi bob

the 12 volt lighting system has very low wattage bulbs and as a result only draws low amps, hence the lighter wiring.

the 12 volt fridge draws about 6-8 amps when running and as much as 12 amps when initially turned on, so it is necessary to use much heavier wiring.

geoff 'n jude

[shesgotthelook]

Hi Bob, as Geoff n Jude said, the fridge draws a large amount of power. It is advisable to run it off 12v car battery only whilst you are travelling. I used to have a van that had a 'fridge switch' in it which sensed motion. Once you pulled up it cut the battery power to the fridge so you didn't end up flat.
I'm not sure that any independent battery system would be able to run a fridge for very long. That's why so many vans have gas as an option.

[King Fisher]

I personally would run the fridge wiring to the caravan battery which is then connected to the car for charging. The caravan battery will then act like a capacitor and dampen out any fluctuations in voltage that can occur from the car's electrics (especially during starting). You could also look at putting an automatic voltage cutout between the caravan battery and the fridge. This would allow the fridge to run off the 12v caravan battery for a while but not allow the battery to flatten too much. Also as suggested a simple switch to the fridge can also do the trick too, so long as you don't forget to turn it off before the battery is flat...

With a 130 amp battery and assuming 6amp draw then theoretically 130/6=21.6 hours. But in reality the voltage drops off as the battery flattens, so I would suspect you could get about 12-14 good hours of fridge use before the battery is noticeably flat.

[mibosa]

Thank you all for your responses, which will now give me something to think about. Regards, Bob

[mibosa]

Back onto the topic of 12 volt power, I have conducted my research and have decided to go with the option of running B & S 6 (16mm2) cable from the car battery through a solenoid and using Anderson plugs at the rear of my car and front of the caravan to the fridge in the caravan to power the fridge whilst driving to my destination. During any stops along the way, or any time where I have forgotten to disconnect the fridge from the power supply of the car battery, the solenoid prevents the car battery from draining.

The entries within this thread previously about the wires going to the 7 pin plug (possibly number 2), can these wires be used to run to the caravan deep cycle battery to provide a trickle charge whilst driving to my destination, albeit smaller wiring that the B & S 6 cable as it is only for the purpose of proving a small charge.??

Would powering the fridge via one power line and charging the deep cycle battery through the 7 pin plug wires be too much for the alternator in the car?

My 66 Ambassador has white wires coming into the space beneath one of my table seats and go to an old bakelite 3 pin power socket near to what appears to be an old battery box base, so without having properly traced the white wires, I note that the number 2 in the caravan 7 pin plug has a wire in it.  I presume that the previous towing vehicle powered an under-seat battery which was used to power the 12 volt globes in the oyster lights which I have removed.

Thank you in advance for any assistance.

Regards, Bob.

[Koala]

Hi Bob, I know that some people do use them but I would not run anything to run a fridge or charge a caravan battery through the standard caravan plug as is simply not up to the job. There is however a 12 pin plug caravansplus.com.au/catalog/product_info.php?products_id=1660&osCsid=3hs0kbkpjh22d9t0qs1qns60g1 which is designed for heavier loads but a Anderson plug is best.
What you propose in your post is close to being correct. Run heavy wiring at least 6mm (you do not need heavier wiring unless you intend to use the 2nd battery as a start battery) from your car battery through a Anderson plug to your caravan battery using a fuse at your car battery and a disconnect solenoid as you describe or one of these www.redarc.com.au/products/product/smart-start-sbi_12v_100a/ or www.redarc.com.au/products/product/smart-start-bcdc/.
You can then run eveything 12 volt including your fridge directly from the battery in your van. I only use a 14amp/hour battery in the van and this is sufficient to run the fridge for at least a half hour when it is down to temperature without the car running.........the car battery will not discharge. If stopped for longer periods turn your fridge to gas.
This is the system that we used for 3 months travelling in our van without any problems. We even on occasion spent 3 days or so free camping without the van being connected to the car or 240 volt and never ran out of battery power in our van.

Koala

[2up]

Hi all, just been reading this thread. I put a deep cycle 200amp battery in the ute tub and a redarc smart start with fuse from the home battery ie car battery using b&s 8mm cable. I bought these off eBay they were substantially cheaper. The redarc smart start I got from a seller in Bairnsdale and the battery from a solar power out let in Preston. The big Engel in the car is never turned off and never flattened the battery. Deep cycle batteries are for this very purpose, being drained then recharged whereas car batteries to not take to kindly to this type of treatment.
PS just checked invoices , saved about $ 300 from the 2 sellers
Cheers Les

[cobber]

Anybody and everybody 

When playing with your vehicles electrics and fitting extra components, don't neglect to test for 'stray voltages' in the system when you've got it all installed. The more 'stuff' you connect to the vehicles electrical system the greater the potential for problems to be introduced.

This site details the test for both chemical and stray voltage electrolysis, wouldn't hurt to do it before you start the modifications.
www.ve-labs.net/electrolysis-101/how-to-test

I only mention it because, in the long ago, I've been inconvenienced by stray voltage electrolysis.
vintagecaravans.proboards.com/post/14168

Cobber.

[mibosa]

Thank you to all of your responses. Regards, Bob

[natho]

Hello all
Just got my hands on an old 1982 14 foot Millard caravan
Wondering how the 12v lighting in the van works
The outside traffic lights all work but non of the 12v lights inside the van are turning on, no internal battery or wiring to connect a battery!? So wondering how this was designed to work off car battery to use 12v lighting?
Any tips legends?

[Koala]

Hi natho and welcome to the forum.
Without seeing the van I can only suggest a couple of things.
Since 1982 many people could have fiddled with your van so anything is possible. Some vans were wired for the 12volt lights to only work when the park lights of the tow car are turned on. What is more likely is that you will find a couple of spare wires hanging around the draw bar somewhere or maybe hanging down under the van which are not connected to anything. Keep looking you will find it.
These days with LED globes readily available and the 12 volt only used for lighting you can get away with a small gel battery in the van with a 240 volt charger and don't worry about connecting to the car unless you intend doing a lot of travelling. I have 28 amp battery capacity (2 X 14amp) and have free camped for 4 days without running out of lights.

Koala

[shesgotthelook]

Re reading this thread, the final outcome with the 62 Viscount- Auto elec fixed the wiring so 12v would run off car. Alternatively, what I thought was a 240v outlet underneath the van, turned out to be a 12v inlet! So as with the globetrotter, we wired a 3 pin plug to some battery clamps & Bob's your uncle! Same for our Phoenix caravan, battery leads under seat & home made adapter to connect to battery.

[Rattles]

natho - The above Diagram will give you an Idea how a Caravan without a House Battery may be wired,
Pin 2 was used for many years as an Auxiliary Feed and this was changed with the advent of 3 way fridge and 12pin Plugs.

The tug will need to be wired to suit, however mos late Vehicles are wired so that Pin 2 is used as a reversing light(newer Standard),
a Quick test to see if the Caravan and Tug are wired as above is to plug the Caravan into the Tug Select Reverse with the ignition on
(Tugs Reversing lights on) and the 12v Lights in the Caravan should glow.

If you only want 12v lights for a one night on the road and then stay at a Caravan park the connecting a fused wire to the battery
from pin 2 of the 7 pin plug will suffice. JUST Remember that is best to limit the number of lights on and duration of use,
each lamp is usually 21CP (18Watt) which is 1.5 Amp each as a flat battery in the AM is a real PITA.

However if longer periods of off grid are required the a house Battery +++ will required,
also if you have a 3 way fridge then it will require a switched supply via a Anderson plug/12 pin plug pins 8-12.

PM me re contact via Skype if you require more information and or tips on 12v fault finding.

Hope this helps.

Rattles