to start off, I am new to the world of Dodge. I have never worked on anything except Ford and GM products. My girlfriend has a 99' Dakota with the magnum V8, 4x4, automatic.
my problem is that the truck goes from 2WD to part time 4WD and that is it. Sometimes you can get into neutral and that is it. I can't even come close to getting it into 4 hi or 4 low.
any advice would be apreciated ...

 

are you putting it in neutral when your trying to go to 4low?
it could just be a lil seized up by shifter. just get underneath and hit the shifter with some penetrating lube and try and work it back and forth.

 

I assume that you have to truck completely stopped and that transmission in neutral, correct?

If you are getting it into part time 4wd then it should be in 4-hi as all there should be is 2-hi, 4-hi, N, and 4-low if she has a floor shifted dakota.

 

Yes you need to have your tranny in neutral in get it into low. Then try it. If you still can't get it in try doing it on a hill and with the tranny in neutral slow drift while trying to put it in low.