A "relay case" containing electromagnetic switches received signals from the governor and push buttons and then controlled a coupler, a decelerator to close the throttle during gear changes, and a solenoid to select operation of the reverse-first or second-third shift rail, using a reversible electric motor to engage the gears. The system was thus entirely electromechanical, without hydraulics, pneumatics or electronics. The relay case was located in the front trunk. On cold days, with no source of heat in the trunk area, the relays would freeze and required the "Open, Push, Whack, and Jump". Essentially, the driver had to open the trunk, push the Drive button on the dashboard, whack the relay box, and jump back into the moving vehicle. On extremely cold days, the relay box was unreliable and intermittent, seemingly having a mind of its own.