Hi, I'm after a 12v feed in the boot of my 14MY XF to act as an amp remote turn on. I have been told that one of the wires into the amplifier does this that I can tap into.

However, my multimeter is showing it giving a 12v feed all the time. I have even flicked the boot lock and alarmed the car to trick it into going to sleep. I've even waited 20 mins as someone said it takes a while to power down

Am I doing something wrong?

Thanks