[s-cars] Proper Solder Technique?

[Jim Bonnet]

on this topic.. I was trying to solder the big-red pad wear sensors to
the factory wiring harness on the urS the otherday..

my question: What makes a wire _not_ want to take solder and how do you
make it?

The ends of the big-red sensors tinned ok, but the wires in the car
didn't want to take the solder. so I just twisted the ends together and
heat-shrinked them.

thanks!

Jim