Help! Remote Acc Turn On? Factory JBL Amp

Hi folks,

Trying to find an Remote/Accessory Turn on to turn on my JBL MS-8. I tapped into the grey acc turn on at the JBL amp (L31B Pin 12 in diagram below), but I believe this is only used to turn on the Bluetooth phone system. I cut this and wired it to the JBL MS-8 Rem In, but it doesn't turn on. I think I read somewhere that the factory amp is always on when the car is powered on.

Does anyone have any suggestions where I can get a remote/accessory turn on when I turn on my JBL Factory HU?

Please help this noob out! Thank you so much!