The SAE J1127 and J1128 standards define two classes of automotive vehicle wiring. SAE J1127 covers heavy gauge *battery cables* (e.g. starter and chassis ground leads) and SAE J1128 covers lighter *primary wires* used in general purpose wiring harnesses. In this article, we review the J1127 and J1128 wire standards, the extent of testing performed on these wires, how they stack up against aerospace wires, and if there are parts of these standards that could benefit their aerospace counterparts. Read more