[Porsche944]

Swapping starters is pretty much a "no brainer" because there are only TWO connections to worry about. The big wires go to the big terminal, and the small wire goes to the small terminal.

If the starter does not crank the engine when you turn the key, then you have an open between the battery, ignition switch and the solenoid. The first place to check is the connectors near the brake booster. Look for one with four wires. Make sure this connector is tight and the connections are not corroded or dirty.

If the starter still does not crank the engine, then you may have a faulty ignition switch or you may have an open between the switch and the solenoid.