12v AC Power in boot - Switchable?
 

I travel with a cooler box in the boot and plug it into the 12v supply on my Mk2 Volvo V70. This 12v feed keeps the cooler box some 20 degrees below ambient cabin temperature and has been used on 10+ European holidays, with very good results.

Anyway, I know it sounds like a lot of effort, for not much reward, but I'd like to make the 12v boot AC power feed switchable from the dashboard and to be more exact, from a spare button blank next to the DSTC & Car alarm buttons; in front of the automatic gear stick.

This might mean running a cable from the boot to the dash, but does anyone know what I could alternatively splice into which is already running front to rear for the 12v power in the boot (unless of course the current 12v cable goes to the battery in the boot already) and is one of the existing switches (to replace the blank, currently in place) suitable for a 12v toggle on/off?

the cabling is easy, it really would be easiest just to run a pair down side of the car, probably via a relay as well I'd have thought (or a correctly rated switch depending how many amps are being pulled)

the tricky bit from what I've seen would be trying to fit your own switch in the AC panel which you don't really want to take apart and mess with, party because a) disconnecting it causes SRS faults unless the battery is off at the time (at least bear that in mind) and b) on the back when you turn it over it's all encased and you'd have to hack it apart to fit a switch

personally I'd put a switch somewhere else for simplicity, under the dash by your right knee maybe, or inside the armrest box would be tidy

alternatively you could very easily make it ignition switched by splicing into the back side of the tow connector (the plug hanging down by the spare wheel) from the sidelights output (check for ignition switching using a meter) and running that to a relay which switches the ciggy lighter plug

Spare blank switch
 

I have a blank switch, I can replace already

that's not actually a switch though is it, it's just a plastic cover (unless I'm misunderstanding)

do you mean as in you can drill a hole in it to fit a switch? because like I say from behind that's not as simple as it might seem

you would have to take the back cover off the CCU and if I recall correctly there is a circuit board in the way as well which you really don't want to mess with IMO

What Stuart said, there's a very busy looking PCB almost immediately behind those. You really don't want to be messing around there! Your best bet is to put a switch on the surround around the gear lever.