I have had the crimped connectors fail on that lead on other GM vehicles. The result is resistance which becomes an issue at higher current levels, as could occur with an inadvertent short. The last one I had was an integral part of the positive battery cable - All 98" of it through the looms and retainers, over the cradle, down the frame rail, and back to the starter (not fun).
I'd wager a small sum that @greentraverse
is correct, and your best bet is to trace out that lead.