before trying to replace the ignition switch try spraying a small amount of lubricant into the keyhole and insert key and wiggle it in the switch to see if the keepers are stuck. if it works it could save a lot of time and money
If you mean which wire goes where on the back of the light switch assembly, google MSD's free online instructions for wiring their kits It'll show the clips on the switch and the factory wire colours and where the go
The 1992 Plymouth Cold ignition switch is held in place by a retaining ring. Remove the retaining ring at the top of the ignition switch. Pull the ignition switch out. Remove the wiring harness from the ignition switch. Reverse the process to install the new ignition switch.
This almost has to be a bad switch. Replace the switch and it should work correctly. It is on the column then the it is not so easy. Have someone do it. If it is on the dash these are pretty simple. Just unplug them then unbolt it then replace. Good luck.
I believe it's a poor ground contact possibly within the switch itself. if your car is rusty look for external ground contacts and make sure that they are on clean shiney metal. If all looks good i'd replace the switch.