Gen 4 ignition cable connection- where?

Hi all. 

I'm busy installing a compressor in the engine bay of my gen 4 - I need to connect the rocker switch to the ignition somehow/somewhere - so that the compressor can only run when the ignition is switched to on. 

Any recommendations? 

  
 

Hi,
I assume the switch is going to power a relay, the relay connected to the battery to power the compressor. I only say this to ensure the switch is a low current circuit.
If so is the fuse box above the accelerator pedal as in the G3?
All you need is a piggy back fuse holder and place it in a circuit that powers off / on with ignition such as the heater blower. Your manual or fuse box lid should tell you which fuse is which. Place the spur in the fuse location, put the fuse in the spur, put a 1A fuse in the spur wire, use this to power the switch. It's plug and play and causes no damage. Most of my devices (LED light, Dash Cams) are powered this way. 
Hope this makes sense. Only do this if you are switching a relay that will feed the compressor, otherwise the current could be to high.
Fuse spur sold at all good motor factors.
 

Thanks Scimike,

Yeah I've done this for a few items already, easy solution, good shout.

I was hoping for a more local (drivers side footwell) as the fuse box is on the passenger side on the gen 4. So maybe an unused connection I could tap.

But yeah, seems like I'll have to extend the wire to the fuse box. It is to a rocker switch, so no real power needed, the pump is connected via relay to the battery. Cheers.

Ah ok - bit more of a run to fuse box.
is the USB power socket switched with ignition?
Sorry don't know the G4 cables as well as my G3.

USB power socket is a tiny four pin connector and is most likely a 5V connection taken off of the head unit - I would suggest the 12V power outlet that's just a few inches away (at least that's where it is on my gen 4).

There are also any number of ignition switched power feeds on the driver's side above that rocker switch - for example the power mirror controls - you're not using to power the compressor, just to power the relay - so not a great deal of power draw.

Did you also think about a D+ Cable? This will only have power if the generator generates electricity. With a D+ the compressor would/could not run before the engine is running.