ranger won't go into 4 wheel drive.

i own a 2002 ranger edge 4x4 with 93000 miles on it and it will not go into 4 wheel hi unless the cab is warmed up, then it goes in with out a hitch. does anybody know what i can do to make this problem go away? i have replaced the shift motor and no differance.

Since you say it only works after the truck warms up I would venture to guess that there is a problem with one of several things. All of the electronics for the 4wd system are in the dash, so I would start there. My first thought is a bad or loose pin in a connector. Then I would look at the components themselves. If you need wiring diagrams I think I may have them.