hello i just bought a 04 jeep grand cherokee 4 x 4 how does the 4wd work on it likeou put it into 4 full time and 4 low and does the light on the dash come on i put it in part ime and the light on the dash said i was in 4 part time but when i put it in full time or low it dont and do you put the gear shift in N to switch the 4 wd from 2 to 4? and do you have to back up after you take it out of 4 wd to unlock the hubs or does it do it it self PLEASE HELP thank you

put it in nutural then put it in 4 wheel drive but on my 95 it says full time when im in 4 low and the hubs will unlock by itself