Does it mean all this while it was the door actuator acting up.

 

In my case I got the SSN warning and the stealership found many DTCs that made no sense, with only 2 codes that did make any sense:
B1318 = battery voltage low
B1239 = traction battery blend door actuator

They blamed everything from the MECS pump (which CAN'T even code, since there's no code for it anyway!!) to the high voltage batteries since they either wanted to make money off me, had no idea what the problem was, or a combo of both. LOL

I simply replaced the old tired 12V battery and haven't had a problem since, having driven thousands of miles in hotter weather than what I experienced the original problem in. I honestly think what happened with mine is the 12V system drained to a point that the Blend Door Actuator couldn't operate properly, and that's what triggered the SSN.

As for your specific problem, have the stealership confirm whether they're still seeing the B1318 battery voltage low code. The fact you've had 2 batteries, a fried cable in multiple spots, etc, makes me think you have a similar problem with the 12V system causing the blend door actuator issue, which in turn could cause the SSN warning. Have they verified everything else on the 12V charging side, like alternator, etc?