On these particular wires to rectifier I prefer to use a solderless crimp connector, but also soldering them in place. Once you strip your wire slip on a piece of heat shrink and slide up wire, and slide insulator off connector and on up the wire, then crimp terminal on. Then also solder terminal in place, and when it cools slide insulator back down over spade connector and heat shrink the connector to wire joint. Guaranteed good continuity come hell or high water.