[A930Rocket]

The pix seem to be a stair step type crack that would indicate the underlying structure is settling or has settled from the looks of the age of the house/material. porbably won't settle any more at this point.

I'd scrape the old mortar to remove the loose mortar, wash the impacted areas (pressure wash it if you can), then parge with some ready mix mortar, cut in with a paint brush and paint the open areas with a roller.