Most likely your STP signal is shorted to ground if you didn't touch the stop light switch behind brake padel. you should have P0504 code. If you dont have any error code then your stop light switch is broken (highly unlikely).
Was trying to wire up an arb rear bumper, didnt do anything on the truck but plug in the bumper (previously wired for a 100). Went to doble check lights, now no running or brake lights and starts but wont go into drive unless i manually override...