Help ID wire under hood

[TheDude]

Hello, could use some help IDing a wire up front at the passenger side front corner. It's switched 12v and from the location and length of it, seems like it could be what should be used for the ignition or even connecting to the alternator. It's a two wire connector but only has the one wire. It's yellow with what looks like a faint faded red stripe. Appreciate any feedback,

Thanks

 

[midlife]

Normally, that is green/red. It's the lead to the alternator harness.