I have a 99 expedition awd. It is stuck in low lock. I've tried unhooking battery, Backing up in neutral for. In Neutral with brake on. It doues not have the plunger on front axl, Nor can i find vacuum lines on firewall. I've been reading forums for a week. Also speedo is same as rpm's Also took out fuse 104 and put new in. Maybe bad shift motor or switch? Need help. anyone?