I want the car to crank but not start how would you hook up a switch any help. Thanks.

 

Put your switch on the pink wire from the ignition switch. It is power to the coil. Easiest to do this off of the steering column. You should be able to unpin it from the connector and use male and female spade connectors so you don't have to cut anything. Heat shrink and tape the end you unpin so it doesn't ground out anywhere.