I did some research and can't find anything that really pertains to my issue..2003 f150 5.4 king ranch 4x4 dial on the dash. One day it worked fine and when I switched it into 2wd I heard a really loud grinding nose coming from up front and it did not kick out until I turned the truck off and back on. Now 4hi does not work at all, the light always comes on the dash followed by the click of the solenoids. In order to get the 4x4 light to go out I have to shut it off and back on. 4lo light comes on when I switched it over and the truck tries to overpower the brakes and lurch forward and same thing have to shut it off and on to get back to normal 2wd. I crawled under the truck and unplugged the vacuum hoses on the actuator and verified that suction alternates when a hand flipped the switch in and out, the front drive shaft does turn when moving forward in 4wd, the actuator lever moves freely in and out when the switch is turned. I really don't think the whole front diff is shelled out but I haven't pulled the cover. Is there any other electronic parts on these trucks to check or something special I may be missing? Everything I've checked is working fine except the front wheels getting power lol