The solenoid is a part of the starter motor that is responsible for engaging the starter gear with the flywheel of the engine. When you turn the key, the solenoid is activated and the starter motor begins to turn, engaging the starter gear with the flywheel and starting the engine.
If the car starts when you turn the key, it means that the solenoid is working properly and there is no need to cross it. Crossing the solenoid would bypass the normal electrical circuit and could cause damage to the starter motor or other electrical components.
