jumpstart melted jumpstart wires??

I have jumpstarted many vehicles, but this was weird. I tried jumping my dead battery in my Ford Ranger from my wifes Ford focus. This is what we did:
She had her car running and I clamped one positive wire to her positive battery post and the other to my trucks positive terminal battery post and then I attached the black negative wire to her negative post, and then I attached the other negative to my trucks frame. (Big huge spark).
Within 30 seconds the jumpstart wires became so hot they started to melt and I grabbed them off both vehicles. (burnt my fingers too)
WHY Did they do that??? Did I hook them up wrong? Her car is fine, but mine is still dead battery.

I purchased a brand new set of jumpstarting wires and used 16' of 6 gauge jumper cables. After we connected the wires exactly the same way as before there was no spark or anything. Did I fry my trucks battery or solenoid?

you may have fried something, but you will only be able to tell once you have a working battery. If you're really un-lucky, you could do as much as fried the whole computer, but that rearly happens. As for jumping a car, ALWAYS ATTACH THE NEGATIVE FIRST - the negative (black) is a ground, so you want to hook it up first so that the juice won't be looking for a ground to jump (spark) to.
when jumping, always connect the negatives first than the positives. Some people say that you should clip the cables onto the negative of the dead battery before that of the good battery, but that is not as critical.
As for the cables getting hot, it may be from the sudden jolt of power, or it just may be that they were old and/or the resistance of the wires was so high that it was more than they could take. Good luck.

I bough better jumper cables (8 gauge) and all was good to go. The older ones were only 12 gauge and could not handle the current.

12 Gauge jumper cables?!?! give me a break! I use 4 gauge jumper cables.

No wonder your cable fried.