'98 Mountaineer 4WD Issue!

[alex95]

ok so I have a 4.0L 4WD 1998 Mercury Mountaineer, the issue is when you put into 4Low it wont come out (yes I have it stopped and in Nuetral). The front end is locked in because there is bind at slow speeds, BUT it isnt in low range. I am unsure if it does this in 4Hi also, if so it will let you into 4Low, but then it wont com out of 4 "low". this started after a simple engine swap (Factory ECU was retained) could this be a connection issue? or just bad luck?
Everything but the engine has 298,000 mi on it

 

[alex95]

*UPDATE*
When the transfer case is unplugged, it does come out of 4WD, no binding when making tight turns. But the 4Low light on the dash does stay on. And I did notice that when it's just keyed on, the 4Hi indicator doesn't illuminate, only the 4low. And input on this would be greatly appreciated