rdunniii. Bummer. Factory soldered wires is a good idea. Hopefully ScottK will weigh in on his soldering technique so we can all profit from his success.
I've been doing other things and haven't yet done my first Select 4.0 L. I've always planned to pre-solder wires on the pads on my workbench with the decoder stabilized and using my variable heat soldering rig with the best possible tip from the many tips for this soldering station. I'll be extra careful now that I've heard your sad story. So, thanks and better luck next time.
Bill