Just bought a 2001 4.0 4wd. When I start the engine I have no 4x4 light on dash. Moving switch from 2wd to 4lo or 4hi does nothing. No lights, no clicks or other sounds, and no 4wd. I know I have a switch, control module, and actuator motor. I don’t have a fuse diagram (no manual with truck, I have one coming) assuming fuses are good, how do I troubleshoot the system. I don’t want to just throw parts at it. I would think the switch was easy to check, but likely not the problem as I have no 4lo OR 4hi.