need wiring diagram to tap into speaker (+) (-) RR and LR also accessories and constant power.

Ok. First off, does the amp have built-in crossovers? If not, you'll need to put one between the head unit and sub otherwise you'll blow the sub because it's not designed to handle anything over 300 Hz, maybe a max of 500 Hz.

Secondly, you didn't tell us what audio system is installed, so I pulled the schematics for all of them to save time back and forth asking.

http://www.dropbox.com/s/lu9chouedus6kvs/F150%20Stereo.pdf?dl=0

the 2014 f150 xlt crewcab. I' m putting in a bass link sub box. Infinity, it has crossover and accepts high level audio inputs. I'm looking for the factory diagram of the head units wiring harness. I want to splice of right rear (+) (-) and the left channel. also want to splice into accessories power for my remote power.

Switching power on most stereos is usually either the single blue wire or the orange wire.