12v auxiliary power outlet in the boot (Mk3)

[brutus-1965]

Hi all,

I would like to have a 12v auxiliary power outlet in the boot of my 2014 Yaris.

Without pulling all the plastic trim out does anyone know if there is a 12v accessory or ignition (I dont want a permanent 12v live) feed in the boot ?

I dont think the 12v boot light is a suitable sourse.

Thank you

[flash22]

The lighting circuit wiring will not be heavy enough, wire it from the internal fuse box at a push you can use a fuse tap

you can pick up a ground anywhere on the body

[Guest]

I did abandon a post because I suspected you would come along Bob!

Yes, lighting no good and will no doubt be a permanent 12v too.

I suggested possibly piggybacking off the existing 12v acc. socket fuse and running a wire to wherever a new outlet is required. With an added caveat to make sure that the combined socket load will not exceed the 15A maximum fuse rating.

I did suggest possibly tapping into the rear window wiper circuit, 12v ignition switched? I am not a fan of cutting wiring and soldering in a tap though.

[flash22]

A fuse tap plugs into a fuse holder, the yaris uses Low Profile Mini fuses, tbh i would rather tap a wire and do an open crimp or soldered connection

 

[brutus-1965]

All good points thanks all.

The plan was to use the 12v in the boot for something like a coolbox and also a supply for USB chargers etc for the back seat passengers.

I have bought some nice looking 12v auxillary sockets so I am tempted to not only put one in the boot and connected to the wiper or heated window but I think I will also fit a socket just behind the end of the handbrake lever (by the cup holder) so it is easily acceible to the back seat passengers.  I already have a 3 port 12v socket tucked in the front of the centre console which I use for phone chargers etc and will be the perfect place for a connection to the socket just behind the handbrake.

All the USB charger accessories combined would be no where near 10A.

Has anyone seen a YouTube link to how the boot plastic trim comes out ?  Doesn't matter if it is driver or passenger side; just so I have access to the wiper/heater window wiring.

[Roy124]

On joining wires, I like those guillotine clips.  Fasten over the source wire, slide the off-take wire into the blind side, clamp with pliers, close cap. 

[brutus-1965]

If you mean scotchlok then I prefer to solder.

The one behind the handbrake is already done.

An old 2 litre water bottle cut down to size fits nicely in the cup holder and keeps stuff upright.

Next is the one in the boot but I might have to remove a bit of plastic first.

[flash22]

37 minutes ago, Roy124 said:

On joining wires, I like those guillotine clips.  Fasten over the source wire, slide the off-take wire into the blind side, clamp with pliers, close cap. 

IDC crimps have their place and automotive is not one of them, over time they can cause corrosion as they are not sealed also the blades can and do cut the strands, vibration and movement is a killer

Open barrel splice crimps are what oems use - https://uk.farnell.com/amp-te-connectivity/485043-1/terminal-open-barrel-splice-crimp/dp/1557608

[bathtub tom]

2 hours ago, brutus-1965 said:

The plan was to use the 12v in the boot for something like a coolbox

Those things can draw a lot of current, make sure that whatever you do the fuse, wiring and everything else is up to it.

[flash22]

Take a fused 12v direct from the Battery and use an 87 4 pin relay to switch it

[brutus-1965]

Agreed.

The big coolbox we use in the caravan draws 5A which I know can drain a Battery pretty quick as I found out when I forgot to unplug it at night resulting in a flat'ish caravan Battery the next day.

Rather than a switched relay supply to the boot (a simple spare headlight type relay would work) I think I might use one of the caravan split charge relays.

https://www.maypoleltd.com/product/mp2881b-20a-self-switching-dual-charge-relay-2/

These split charge relays work from a single heavy duty supply from the Battery through to the back of the car.  There you connect the split charge to the supply and earth to the body.  The electronics inside the split charge provide a permanent positive and also a switched positive supply when the battery voltage rises above 13.5v.  For safety when the voltage drops below 12.9v the switched supply is disconnected.  This normally only ever happens when the alternator is charging so when you switch the engine off the split charge disconnects the switched supply.

This also means I do not have to splice into the main wiring and can if need be simply be removed.

A pretty nifty bit of kit.

[Derek.w]

I just use to use a 12 volt relay for control (simlar setup to charging a auxiliary caravan battery)

and wire the power direct from the Battery via a fuse.

[flash22]

It's controlled by a switch live so you don't need anything fancy, if you leave the car in aux mode it will turn its self off after 15 min's

also £15 vs £3 for a standard relay

[Guest]

21 hours ago, flash22 said:

A fuse tap plugs into a fuse holder, the yaris uses Low Profile Mini fuses, tbh i would rather tap a wire and do an open crimp or soldered connection

 

Once again, personal choice. I hope that's still allowed?

Again personal preference, Scotchloks or similar, never in a thousand years.

A fused supply from the Battery and incorporating a relay is an excellent.