Vibration System and Steering RD 12 / RD 12Awc_tx000668gb.fm 606.3 Checking the Vibration Solenoid ValveBackground When the roller’s engine is running, the solenoid (a) of the vibration manifold (b)receives power through the white wire via the vibration switch. When energized,the vibration solenoid valve shifts causing oil flow to the exciter motor. To check thefunction of the vibration electrical system, both the vibration solenoid and the vibra-tion switch should be tested.Procedure Follow the procedure below to check the vibration solenoid.1. Place the key switch in the ON position.2. With your hand around the body of the vibration solenoid (a), turn the vibrationswitch ON and feel for movement of the plunger inside the vibration solenoid.Note: If the movement of the plunger is hard to detect, remove the solenoid from thevibration manifold to make it easier.Is the vibration solenoid functioning?3. Disconnect the vibration solenoid from the harness.4. Place the vibration switch in the ON position and measure the voltage acrossthe connector (b).Is 12VDC (battery voltage approximately 12V) measured?The vibration solenoid has now been checked.Yes ____ No ____Any problems with vibration are in the hydraulic circuit, not theelectrical system.ContinueYes ____ No ____The vibration solenoid is receiving powerand should be functioning. If it is not, it hasfailed; replace it.Continue troubleshooting by checking thevibration switch.