99 Transmission Wiring Harness Problems??

[JDeBusk]

Hi we have a 99 5.4 Expy. Recently had the od light flashing after a lot of googling figured we would try the TCC. Well long story shot Auto Zone sent us the wrong TTC. After he put the solenoid block back in I couldn't take off in drive. We could put it in 1st and go just fine and then shift up to drive and be OK until we had to take off again. So we replaced the whole transmission solenoid block. Still have the same problem. Tonight he found wires that had been burnt in to. So my question is can you disconnect the wiring harness from the transmission without a shit ton of trouble? Also if you guys have any additional info please share. I am ready to drive it off a cliff!