Haven't got answers to all your questions but...
If the wire is getting hot check for resistance somewhere. As an example so of the guys here led me thru the same problem (hot wire) which turned out to be the blower on the front condensor (luggage compartment. It was blowing air ( a fair amount I thought!) but when I pulled it out to look at it I found the motor wasn't spinning freely. I put some motor oil on the drive shaft and that loosened it up considerably and cooled the wire way down.
However I am now searching for a new motor (for the blower) as its 15 years old and still does not spin as easily as it should. I can hear it slightly grinding which I believe is slowing it down, causing resistance causing heat in the wire - so I am led to believe.
This example might serve as a resaon for your hot wire - no blower at all (either the front one like mine or the one in the smugglers box.
I'm no twit in this area, rather.... mostly useless, but I hope this might help.
Cheers
Mark
