k7peh.. 2-0 cable from the battery.. thats for a huge amplifier.
#10 would be plenty big for a 100 watt radio.
#8 if you like to over due a bit.
so anyone doing it your self, do the research, 2-0 wire can hardly be bent...
#1 wire carries 119 amps.
I was sort of guessing by a vague memory of what was installed. So, I think it is possibly #2 wire, not 2-0. I wanted it to handle about an 85 amp load because I was thinking I might want to add a 500 watt amplifier someday with a slave battery. I haven't done that yet.
You also said that everyone's goal should be about learning everything about everything...
The reason I paid someone to do this work on my pickup truck because that particular skill is not only a waste of my time but it does not add one iota of knowledge that is useful to me. I already know I could have strung those wires and done all that work if I wanted to but I chose not to. Since money is not the issue here, I employed those degrees of freedom I have to pay someone else to do this job.
As for continuing the learning process -- that is mostly what I do but it does not involve working on my pickup truck.