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| Illustration 1 | g01073485 |
Fan Control for the Hydraulic Oil Cooler
The main power relay distributes power to the fuse for the fan motor through the 112-PU wire. The 122-BU wire transfers power from the fuse of the fan motor to the coil and contact 3 of the relay for the fan motor.
The temperature switch for the oil cooler provides the ground path for current to flow through the coil of the relay for the fan motor. When the temperature of the oil in the cooler is less than the opening temperature of the temperature switch for the oil cooler, the switch is closed, and the coil in the fan motor is energized.
When the relay for the fan motor is energized, contacts 3 and 4 are closed, and power cannot reach the oil cooler fan motor.
If the oil temperature rises above the opening temperature of the temperature switch for the oil cooler, the switch opens, and the ground path for current flowing through the coil of the relay for the fan motor is broken. The loss of the ground path causes the coil of the relay to de-energize.
When the coil of the relay of the fan motor is de-energized, contacts 3 and 4 of the relay are closed. The power that is available at contact 3 through the 122-BU wire then transfers the power into the G736-PK wire.
The G736-PK wire transfers power to the oil cooler fan motor, and the fan operates.
If the oil temperature falls below the opening temperature of the temperature switch for the oil cooler, the coil of the relay for the fan motor energizes, and the oil cooler fan motor stops operating.
Vibratory Control
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| Illustration 2 | g01073548 |
The main power relay distributes power to the vibratory fuse through the 112-PU wire. Power transfers from the vibratory fuse to the control switch in the propel lever.
When the control switch for the vibratory system is ON, power transfers into the A990-BU wire. This wire delivers power to contact 2 of the vibratory control switch for the drum, the vibration indicator in the indicator cluster, and the solenoid for the front drum. The vibration indicator illuminates, and the solenoid for the front drum energizes.
When the vibratory control switch for the drum is in FRONT DRUM, contacts 2 and 3 of the switch are open, and the solenoid for the rear drum is de-energized. When the vibratory control switch for the drum is in BOTH DRUMS, contacts 2 and 3 of the switch are closed. In this case, power transfers to the solenoid for the rear drum through the C926-BU wire, and the solenoid for the rear drum energizes.