Originally Posted by
Reaper1
If you use waterproof connectors along with self sealing heat shrink the connections should be just fine provided that the wires don't have corrosion creeping up into them. This isn't the preferred method, but it will work. It works on boats all the time (did marine work for 11 years). It certainly is much better to solder at least the alternator feed wires due to the size and amperage. Of course use the self sealing heat shrink on all connections.
For soldering the wires together it is much easier to do if the entire engine bay harness is out of the car. It can be done in the car, but it is much more difficult. For larger wire I like to do free-air soldering...basically using a butane torch to heat up the exposed wire enough so the solder flows into the joint. It is much easier and faster to do it this way compared to using an iron.
Another tip for making soldering easier: use flux. It helps keep the joint clean and it helps the solder flow. Just make sure to wipe the joint off after it cools to remove any excess residue.
As for the wire colors, most of them are the same or close. I know there is at least 1, if not 2 tutorials with pictures floating around on how to do this. I don't remember if I posted up mine or not, but I modify the circuit layout to separate some of the systems as I feel there are too many voltage-critical items being run from one point. Whether it makes a difference or not, I have no idea, honestly.