Information on 1990 "Starter Sensor."

I have a friend with a 1990 Century (V6). His car won't start because when his serpentine belt broke, it hit his "Starter Sensor." and I think it moved it or broke it.
I've never heard of a Starter Sensor. Can anyone explain it and what I would need to do to fix it? Thanks,
Chris.

I have a friend with a 1990 Century (V6). His car won't start because when his serpentine belt broke, it hit his "Starter Sensor." and I think it moved it or broke it.
I've never heard of a Starter Sensor. Can anyone explain it and what I would need to do to fix it? Thanks,
Chris.
Crank sensor behind the harmonic balancer?

What does a crank sensor do?

Sends a signal the ign ctrl mod and the pcm to record rpms, needed to get spark and injector pulse.

The part he needs is not broken. It has to be aligned just right. Does this sound like what your talking about?