Solenoid (Part #90028112) used on terminal tractors and yard trucks. A properly functioning solenoid is critical for reliable electrical system operation on a yard truck. It ensures power is delivered where and when it's needed, supporting starts, stops, and controlled functions. A faulty solenoid can lead to intermittent electrical failures, no-start conditions, or inconsistent equipment response, especially in high-vibration yard environments Electrically actuates controlled circuits or relays to start, stop, or engage equipment functions