In the Navy we never soldered any wires, only crimped. Take a piece of wire and crimp one end and solder the other. Place each end in a vice and wiggle both ends and the soldered end will break. Also, don't put shrink sleeve over the end. If a wire parts at the joint, the shrink sleeve can hold the wire to the electrical connector and cause intermittant problems. Get the best crimping tool you can find and the joints will never fail you. This topic has been discussed before and the crimp guy's think they are right, and the solder guy's think they are right, so do what you feel is best for you.