Does the actuator make a sound like it wants to do its thing? If so, have someone hit the AWD button while he is underneath. Gently tap,tap,tap on the actuator with a rubber mallet or the butt end of a hammer while the dash lights flash. Hopefully he'll hear a clunk and it'll pop out. Drive...
PB Blaster the whole mechanism. Spring and surfaces that slide/rotate on eachother. Take a flathead and push the flat hooky thing (inside the 'U'...not the big hood lever one) one way or another. Should spring back. Happens regularly on both of mine and seen it on multiple tacomas.
A hair different than the usual 4runners posted here…the plowrunner set up! Pushes like a champ with the chains. Big 3, 220amp alt upgrade to accommodate the plow and lights on top of the normal vehicle draws. The frame has beaucoup rust damage in the rear so it’s a yard truck till complete...