Wiring Questions

[AC137]

Im looking to do some wiring of spotlights and had a few questions about how to go about it.

First of all I got a few light bars to wire, the first two are going to be used as reversing lights and wanted to know what thickness of wire to use. The wiring harness that they came with uses 18AWG wire and the lights are 60W, 30W each, so they will be drawing 5 amp total, is the 18AWG wire sufficient? or I've got some 16AWG wire kicking around which says on the roll its rated to 15 amp, so is it a good idea to upgrade to that and use a 10 amp fuse inbetween?
Then I've also got a light bar for the front which is 180W so going to draw 15 amp, should I use 25 amp wire (what AWG is that?) with a 20 amp fuse?

Next is about where to run cables through the firewall, is there only the two points like the ones shown here viewtopic.php?f=21&t=931 if so, is the one behind the engine likely to get hot?

Lastly wheres the best place to get power from the ignition (was thinking cigarette lighter)? I want to have a busbar, something similar to this https://www.autoelec.com.au/ssl/public_ ... 002&cat=29 so when ever I need ignition power I can just connect a cable from it then have a fuse inbetween that, like voltage meters, engine bay lights etc, just keep everything neat

Hopefully there isn't anything I've forgotten

[poppins122325]

Best bet for a light bar i found was the Narva plug and play kit, makes life a lit easier plus its all fused, wired, and ready to go just plug in and your away

Just run the cables through the firewall with the others behind the fuel filter, theres a bolt on boot thats easy to remove and comes out behind the glovebox.

As for the busbar id recommend using a relay on the outlet in the center console, (plenty of room under the cup tray for wiring) and while pulling cable through the firewall pull another set through for the relay and busbar.

For reversing lights im not sure mate, im in the process of updating mine and will rewire it as well, so im holding out for an answer too.

Im sure others will offer there help as well

[NowForThe5th]

18AWG is ok for each light at 30w with a run up to about 2m. For supply from the battery to the relay I'd use the 16AWG. With a 5 amp load I'd go for a 7.5 amp fuse, but 10 will be ok.

For your light bar 10AWG if the run is up to 3m and the 20 amp fuse will be fine.

These are minimum recommendations for a voltage drop of less than 3%. A lot of people like to step up a size and this is generally a good idea.

I'm not a big fan of using the cigarette lighter circuit to power stuff. It's barely able to carry its rating and often linked to other things at the fuse box. I think that finding a circuit that isn't used is a better idea or, ideally, running a line direct from the battery so it's completely independent. You can make conditionality of ignition on by running power through a relay and using an ignition on circuit to switch the relay, that way not putting any excessive load on an existing circuit.

When running cables through the firewall, instead of running separate wires I use trailer wiring cable. It's easier and neater and gives you capacity for the future. I have four passing through the firewall (2 x 5 core, 2 x 7 core) and while my setup is much more complex than most I still have plenty of capacity for things that I haven't thought of yet.

[Cowboy Dave]

As Chris has covered everything else, I'll focus on the bus bar. I tend towards the view that a live bus bar isn't a great idea. If you had to have one it needs to be fused and well covered.

A better option is something like this:

http://www.jaycar.com.au/modular-design-blade-fuse-block/p/SZ2013

It has still effectively got a bus bar down the middle but the terminals aren't live until you add a fuse for each.

They come in different sizes etc. narva makes one as does blue sea. This jaycar one is good in that there are different sizes and they have a negative bus you can add on as well.

[AC137]

Thanks for the advice, the fuse block seam the better way to go and also keeps the fuses neat all in one spot as well.

With the reverse lights there wired straight to the battery because I wanted them as sort of work lights (hooking up trailers etc.) through I feel as though I should need power from the ignition to then be able to turn them on... Likewise I'm adding a voltage meter and want that to come on with the ignition, not always to be on. So if someone could do a little diagram of how to get ignition power with the relay setup would be good, and greatly appreciated. (can I use the centre console 12v outlet as poppins suggested or is it better to use something else?)

Edit: Also should there be a fuse or circuit breaker inbetween the battery and the aux fuse box?

[AC137]

So I've done a little sketch of how I plan to get ignition power to seperate fuse box, just wanted to know if the wiring looks right and again recommendations on wire size.



Also I'm going to have another fuse box hooked directly to the battery, so should there be a fuse or circuit breaker inbetween the battery and the second fuse box and would 8 B&S cable do?

[RHKTriton]

Basically looks OK.

The starting point in designing your setup is what sort of loads (amps being supplied) are you proposing to connect.

Keep the fused distribution box as close to the battery as possible or have a fusible link at the battery end of a feeder cable supplying an extra fuse box.

To have an 'ignition on' distribution box you could use the feed to your centre socket supply as the control wire and then run a beefed up supply to the socket.

[grox]

If you want you can just run -Ve from relay to chassis (85) it's just needed for signal to open connection from battery(30) to load (87) trigger or signal wire is 86 on relay. Any large load to the back I run -Ve wire from battery and not rely on chassis.

[GLX11R]

Hi guys. This thread helped me a lot with wiring!
One question I have though is where are you mounting your switch?

(If there already is a thread on this can someone please link it)

[explorer.dave]

Hi guys. This thread helped me a lot with wiring!
One question I have though is where are you mounting your switch?

(If there already is a thread on this can someone please link it)

viewtopic.php?f=21&t=11733&p=529127&hilit=switches#p529127

Search Forum (switches + electrical)

[NowForThe5th]

Right click | View Image

ntn.gif

[explorer.dave]

Maybe a mandatory "How to search Forum" on sign up?

[GLX11R]

Maybe a mandatory "How to search Forum" on sign up?

GOOD IDEA

[tondo12]

Hi,
I want to throw an extra 2 12v outlets in the back seat for the kids.
A mate of mine showed me this 12v fused splitter, (not sure of the name, but from jaycar)
Im not the most electrical savy bloke. But would i be a to run a cable with an inline fuse straight from the battery to the fused splitter? If so, if the car is switched off will they still draw power.?

[AC137]

To follow up on my original post, have added the relay to the centre console and its powering the fuse box. I've also added 2 figure 8 cables one for voltage meter and the other for usb outlet in the rear (still to be wired up).

Tondo in regards to your questions:

But would i be a to run a cable with an inline fuse straight from the battery to the fused splitter? You don't need a fuse in-between the battery and the fuse box, just work out how many amps the fuse box is going to take then get the correct wire size. (always wire up a bit, e.g. if you going to be drawing 10 amps get 15 or 20 amp wire)

If so, if the car is switched off will they still draw power.? Yes the 12v outlets will always be live, i.e. if you leave something plugged in it will continue to charge and drain the battery, thats why I wired mine the way I did (with the ignition on)

[Cowboy Dave]

I would still fuse the feed wire from battery to splitter (or fuse block). Put the fuse nice and close to the battery end.

[AC137]

Instead of starting a new topic I though id continue from an old one.

I need to add an Anderson plug to the rear for the caravan but was thinking is it possible to have it double up as a plug for the compressor using 8B&S gauge wire and a 50 amp circuit breaker?

From what I’ve understood, the current loss will be too much as the compressor daws a max of 45 amps (Thumper MKII form 4wd super centre) but just though id ask.

[NowForThe5th]

Maybe not quite what you wanted to hear, but here are the numbers....

cable_calc.jpg

[AC137]

Cheers for the confirmation, and yes, not what I wanted to hear but not that big of an issue. Will try rigging something up at the front and keep it as short as possible.

Also is it possible to have the same connection to then charge the battery with solar?

[NowForThe5th]

Probably. Let one of the solar experts (which I'm not), chime in on that.

[ag9111]

Yes
As long as you have a regulator between the solar cell and the battery

[NowForThe5th]

So, here's a tale... I'm installing some LED driving lights, which came with a harness (from 4wd supacentre), and my lights are doing strange things (Here for the "instructions" i followed).... First off, in the normal config no lights worked for me - no high beams, no spotties. After re-wiring the piggy back the driving lights don't come on at all, and the switch - which should control the driving lights - now turns my high beams on or off. Anyone had any experience with this? Clearly, I'm not good with electricity, and not knowing exactly how this wiring harness is wired makes it difficult to rewire.

wire wire wire.

[thatguydrivesatriton]

Problem fixed. After two days, ripping apart that loom and remaking it (twice, with different relays)...

Turns out it was a blown fuse and I can't read a fuse chart. Like the moral of a Disney movie... "The problem was with me the whole time!!"