Where did you guy run your amp power wire from your battery (I am using 4GA) into the cab at? Is there a hole somewhere already you can access or did you drill through the firewall. Any tips would be great!

 

Look here https://www.f150online.com/forums/sh...hreadid=158677

 

I just popped a rubber plug out of the firewall, fed the wire through, and squeezed the plug back in place.

 

I laced a 10 gauge for amp etc. through the near the steering wheel plug. I put a hole in the black plug, so it forms a wire protector. The under the passenger rail sounds great for an amp alone. There is also a grommit on the under the sill on drivers side near the rear of the front seat that works well.
Chris

 

I ran it down under the engine along the frame and along the passenger side then popped up that plastic side step inside the doorway and there was a small hole that i ran the power cable into and wired it into the amp i installed under the rear passenger seat.