I think it is still a vacum solenoid to activate the motor on the transfer case. The solenoid is what says go to the ECU and engages TC Motor and tells the indicator light to come on. Mine is not floor shift, however it did the same thing, changed solenoid on firewall and fixed. I dont think you can buy a true manual shift in a f-150 at all after 04 if not before.
If locking in 4x4, you can tell just by driving as the turns want be as tight or put it in some dirt and see if the front turns the tires spin when you give it some gas you will no the TC motor is working.
Last edited by sglover; 10-02-2012 at 10:24 AM.