[franken]

The tool to compress the tangs on the terminal is a pin pusher.
Your crimpers look to be incorrect, sadly there are many kinds.
If the wires pull out of the terminal after crimping, the crimper is not the right one, or the crimp was incorrect. Sorry...
Ref the pic in post #2933. The crimp of the big end (closest in the pic) is in the insulation to help hold the terminal; the next one is in the bare wire and provides the electrical connection. The crimper should roll the tangs of the terminal in a bit, not just fold them over. If the crimper has U shaped patterns and not rounded W patterns, it aint right. Also, with a less expensive crimper you may need to crimp a few times on the different spots.
The next bits sticking up slightly are what hold the terminal in the connector and what the pin pusher releases to allow the terminal to be removed.

It might be too late, so if you soldered, make sure to try and minimize vibration, wobbling, movement, whatever at the connection. A soldered joint is brittle and more prone to failure when stressed. A soldered joint also depends on a good mechanical connection; solder is an alloy of lead and tin, neither of which are strong.

Sorry if that was TMI.