I have used the solder seal almost exclusively on my 818 after having good luck with them on my mustang. However, as Wayne stated, solder can get brittle where it vibrates, so I don't just slide the wires in and heat up the sleeve like they show on youtube. I actually slide the solder seal down past the connection, twist both wires together (like for a wire nut), then fold them back down on one side of the wire and slide the solder seal back up and heat it. It basically becomes an adhesive heat shrink sleeve at that point, but with some low temp solder to help it hold and help with the conductance.