BMW Repair: 1987 325i will not start, solenoid, flywheel

Question
friends car towed home.All elect works.When attempting start it doesn't make a sound.Did attempt in P as well as N.Jumped out solenoid at starter it spun freely.Any relay or something i don't know about?

Answer
Bad starter.  if you jump the solenoid and it spins but does not spin the flywheel (to turn over the engine) then the problem is in the mechanics used to extend the gear on the starter before it begins to spin, should the resistance be enough, the solenoid may not energize the motor.  you can get the starter tested at most autoparts stores.
-cheers