The main thing to worry about is the size of the conductor itself. You can go with larger sized wire in place of smaller wire, but not the other way around. In other words, you can use 18 gauge wire in place of 20 gauge wire. The lower the AWG number, the larger the conductor, which means the more amps it can carry.
I would not be concerned about one over the other, but I would not use smaller gauge wire than what was used originally. My thought process on this is yes, it would probably work, but the engineers were told to make the harnesses as cheaply as possible. Larger gauge wire costs more than smaller gauge wire, so they were probably at the margin of usefulness for the size wire used.
Pleasant Plains, IL
