I’m having a hard time finding out if an RCA for subwoofers is stock in my 2013 lariat with Sync. If it’s not stock does anyone know of a good adapter

 

RCA.....connector? No. Do you have a sub?

 

yeah and RCA connector , I have 2 10 inch subs that I wired into my back door speakers but I have an amp on the way and want to know if I need and adapter for the head unit

 

I meant do you have the Ford/Sony factory sub. Which Ford stereo do you have? But, why would you need to wire into the HU if you already wired into the speaker lines?

All the factory HUs have proprietary multipin connectors. But, they are not all the same setup.

 

Use the speaker-level inputs on your amp and wire up the signals from your back door speakers into the amp.