ELECTRICAL SYSTEM CONTINUED
Switch (Hydraulic Lockout)
The hydraulic lockout switch is a double-pole double-throw (DPDT) rocker switch. The hydraulic lockout switch
informs the ECM that the operator wants to lockout the hydraulics or unlock the hydraulics for the bulldozer
attachment. The switch is located on the right hand console in the cab.
The common switch contact 5 for the input pole is connected to frame ground. The N/C contact at switch contact 4
and the N/O contact at contact 6 provide two inputs to the ECM.
When the switch is in the LOCKED position, the ECM input at switch contact 4 is switched to ground. This indicates
to the ECM that the switch is in the LOCKED position. When the switch is in the UNLOCKED position, the ECM
input at switch contact 6 is switch to ground. This indicates to the ECM that the switch is in the UNLOCKED
When the switch is in the LOCKED position, the ECM outputs a power signal through the solenoid switch pole in
order to energize the hydraulic lockout solenoid. The solenoid is located on the hydraulic relief valve. When the
solenoid is energized, pilot pressure for the implement system will be blocked.
Figure 10. Hydraulic Lockout Switch.