I have a 95 Intrepid just put on new starter now it will die just driving down the highway? Then today it would not go into park?

Optional Information:
1995 Dodge intrepid 3.3L

Already Tried:
when it stops running while driving sometimes you can just restart it, but other times I have to wiggle the wires around the starter and it will start. I finally got it into park but it is still stiff.