Hi, Ive got a 2002 sr5 xtra cab 5sp 2.7 manual 4wd shifter 4wd. The problem is the 4wd drive light doesn't go on . When I shift into 4lo it goes into the lower gearing but the fron diff doesn't engage. Thinking its the actuator switch . Any other suggestions ?

 

Could be anything in the entire system

Check the electrical side if nothing is found check the mechanical parts.