Any way to disengage AWD?

[Declansdaddy]

So I have a 99 Expy 4.6 AWD and I believe under acceleration and when pulling my boat that the AWD is engaging and disengaging. I get a jolting and while going around turn the tires chirp. Is there anyway I could disengage the AWD just to test my theory?

 

[Yudaman]

Brown wire mod. Click here!

 

[Declansdaddy]

^^^ one and done!! Thanks for that.