I put it into gear and it dies.

They've got little barbs on them. You'll need a tubular removal tool to take them out.
Some photos here.
ignition-switch-terminal-difference-oe-vs-standard-us88-vs-molex-10-12-1602-jpg.jpg
Sources for Chrysler type wire terminals

A big thing is to make sure they are not backing out on their own.
I've not had that on the round terminals but others have.
I have had it on the Packard 56/58/59 type of terminals and others. Push the connector in and all looks cood but the metal is hardly touching if at all. Pull your hair out trying to figure out an intermittant problem and everything looks good. Had it on the Ford type coil connector and GM alternator connector. Must be a Jeep thing.