2006 Buick LaCrosse starter issue

Customers car won’t start. Previous mechanic
replaced the starter due to the car not
starting. When turning the key to start
everything blanks out but to starter motor. I
hear a click in the car, but when the car is
cranked I don’t feel the relay in the box under
the hood clicking. I swapped it with a
matching relay in the car and still no clicking
from relay. I know the j-case fuse is good and
I believe the blade few is good, at least
visually looking at it. Does someone have an
idea of what to check next.