JLG G12-55A Service Manual - Manual (Page 158)

Electrical System
9-16 G10-55A, G12-55A
9.8 CAB HEATER AND FAN
9.8.1 Cab Heater Controls
Note: If the suspect component is found to be within the
heater box, the heater box must be removed as a
complete unit and replaced.
a. Cab Heater Controls Removal
1. Park machine on a firm, level surface, level machine,
fully retract boom, lower boom, place transmission
control lever in (N) NEUTRAL, engage park brake
and shut engine OFF.
2. Place a Do Not Operate Tag on both ignition key
switch and steering wheel.
3. Open engine cover. Allow system fluids to cool.
4. Properly disconnect the batteries.
5. Remove screws securing right cab dash panel (6).
6. Pull out panel to gain access to heater control
electrical connections. Disconnect harnesses.
7. Remove heater control knobs.
8. Remove necessary hardware securing heater
control from dash panel. Remove control from panel.
b. Disassembly
DO NOT disassemble cab heater and fan controls. The
controls are not serviceable. Replace controls if found to
be defective.
c. Installation and Testing
1. Check that the variable speed fan control is in the
OFF position.
2. Install the heater controls to the dash panel with
the previously used hardware.
3. Connect the cab electrical harness connector to
the controls.
4. Install the control knobs.
5. Install screws securing dash panel to cab.
6. Properly connect the batteries.
7. Turn ignition key to ON position and check fan
speeds. If further repair is needed, refer to Section
9.5, “Electrical System Schematics.”
8. Start the machine and allow engine to warm to
operating temperature. Check heat control at
different levels.
9. Close and secure the engine cover.
10. Remove Do Not Operate Tags from both ignition key
switch and steering wheel.
9.9 SOLENOIDS, SENSORS AND
SENDERS
9.9.1 Park Brake Solenoid Valve
a. Park Brake Solenoid Valve Removal
1. Park machine on a firm, level surface, level machine,
fully retract boom, lower boom, place transmission
control lever in (N) NEUTRAL, engage park brake
and shut engine OFF.
2. Place a Do Not Operate Tag on both ignition key
switch and steering wheel.
3. Open engine cover. Allow system fluids to cool.
4. Properly disconnect the batteries.
5. Disconnect the wiring connector at the park brake
solenoid lead.
MAL1640
6