Originally Posted by joes06tacoma
Rich was a bit curt, perhaps. But he seems to error on the side of caution with this kind of thing, as we all should. I think He meant well.
I have seen some scary electrical stuff, both in vehicles and houses.
Some from seeing it, and some from personal experience before I new better. Thankfully I never fucked up a house (and I've been working traffic signals for 20 years), and my only vehicle hack jobs have been in the junk yard for close to 30 years... fortunately I was the last owner of all of them and they never did anything more than smoke a little
because advice over the interwebs can be a bit like playing the game "telephone".
Another bingo, which is why I ripped into Badger.
He obviously knows his shit, but that level of "sharing" is going to do nothing but confuse the layman who just wants to mount an amp.
Understanding the limitations of the net, and the big problems of troubleshooting with a 3000 mile long screwdriver and no eyes on the problem, I'm always going to err on the side of safety.
We see these aux panels installed all the time with 100a breakers and wire that is obviously too small (talking 8ga!). That's not a breaker... that's a fusible link between the battery and breaker.
For house wiring, 100a can't even be put on 2ga, even though it is listed as within spec when contained, and free air for 6ga.
Personally, in a vehicle, I am always going to use the "contained" ratings. Even though the wiring is not contained within a conduit and stuffed in with other wires, it is still in a hot engine compartment, and exposed to the elements.
Also my personal opinion is to avoid the use of any solid conductor wire, and any wire smaller than 18ga, simply for durability concerns. I know the factory harnesses go to 20 and 22ga, but they are also carefully routed and braced.
So ya, I'm going to err on the side of safety.
I'm not mass-producing items for market where the difference between 4ga and 8ga is going to break the bank. I don't HAVE to use the minimum acceptable products. The cost increase to add a good margin of safety is a small percentage of the entire project.