Aftermarket stereo issue

Seen various versions on here of similar problems but for my sake ill post for myself tl make sure i can fix the issue, i purchased a dab stereo upgrade kit off ebay with a (sony) head unit, a Pc2-34-2 harness & everything else i needed to get the unit working.
Issue is the radio stays on after i turn the ignition off/lock the car, i tried removing the face & turning the stereo off manually but it still drains my battery to a point i have to get in (using the key as central locking has no power) & rev the engine to stop the battery from dying on me.
I’ve seen threads saying the yellow lead is permenant live & red is ignition, would swapping the bullet connectors over solve my issue?

JamesRG wrote: would swapping the bullet connectors over solve my issue?

Hi JamesRG
It may well do (if they are pins 4 and 7 of the Power part). The wiring for the C3 is not standard ISO with the computer taking control of the power.

Swapping 4 and 7 of the ISO power plug is a fix, sometimes - If the head unit is of a higher power than the factory unit, it would be worth adding extra wiring to the battery via fuse or the cigarette/power socket because the 'swap' trick only works on lower power head units.