Keyless tailgate wiring install ? 2013 crew/long bed
 

Trying to find the wires to unlock and lock the doors so I can install a keyless entry lock on the tailgate. The wiring chart shows : Lock(Gray/Brown) Unlock(Lt Blue/Lt Green or Purple/Gray in the driver side kick panel. This is for a 2013 F250 Superduty Crew Cab Long Bed.
I tried all the wires with no luck( not sure if I was grounded properly). Just wondering if anyone has had any experience with this ?
Thanks in advance if you can possibly help me !
Mark