Burnt wire

Evening, gentleman. I found something very bothersome that I'm hoping one of you can help me out with. While trying to clean up my engine bay a little bit I came across this fried wire. I've owned this car for 50 years but I somewhat put it away over 30 years ago when I started having kids and chasing Sports Etc. I have no recollection of this happening and I think if I did I would have straightened the problem out and I haven't come across any electrical problems. I am the second owner, buying it when it was 2 years old. I can tell you that it had an aftermarket air conditioning system on it which I feel was a terrible install but I'm not saying this had anything to do with it, just that it did have some bizarre wires and hoses that were routed through the firewall. In case it's not clear to anybody this is coming from the plugs on the driver side of the firewall right next to where the trans kickdown is. I can find absolutely nothing anywhere near this where it would have connected to. Up close it appeared to be wrapped in black electrical tape but on further inspection I'm thinking that might have just been burnt insulation and the picture seems to bring it up as a blue wire . Do any of you more learned fellas know the answer? Electricity is my least favorite sport.

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