Komatsu 830E-AC Shop Manual page 822

Electrical Circuit:
A switch is located in a box (2, Figure 19-2) attached to
the right upright structure beside the automatic lubrica-
tion system grease reservoir (4) that may be used to
disable the shutters during warm weather.
The shutters are normally activated by the engine
ECM. The engine controller monitors coolant tempera-
ture and provides a signal to close the shutters when
the temperature is too low.
The engine ECM will provide a +24VDC signal (circuit
65S) to energize relay K5 located on relay board #8.
See table 1 for specific temperatures where the ECM
will send a signal to close the shutters. This will close
the N.O. relay contacts fed by relay K3 which provides
+24VDC when the key switch is ON. Current through
K5 is fed through the shutter disable switch (closed for
shutter operation) and will energize the shutter sole-
noid valve to direct oil to the head end of the shutter
actuator cylinder to close the shutters.
If the cab air conditioner is switched on, relay K3 will
energize, opening the +24VDC circuit (712ST) supply-
ing the shutter control solenoid, preventing the shutters
from closing.
Refer to the electrical schematic at the back of the
shop manual for additional wiring information.
M19-4
FIGURE 19-2. SHUTTER ENABLE SWITCH BOX
1. Right Upright Structure
2. Switch Box
3. Harness Wire to Shut-
ter Solenoid Valve
MAINTENANCE AND REPAIR
The solenoid valve (5, Figure 19-1) and pressure
reducing valves (3 & 4) in the hydraulic circuit are fac-
tory set and not adjustable. If a valve is inoperative,
remove and replace the complete valve and body
assembly.
Relays K3 and K5 are plug-in devices that may easily
be replaced if defective. The relays are located on
Relay board #8, located in the electrical cabinet. Its
location may vary due the date the truck was manufac-
tured.
The shutter assembly should be inspected for physical
damage and to be certain it opens and closes com-
pletely without binding. If necessary, adjust actuator
cylinder linkage to ensure proper operation.
Radiator Shutters
4. Auto-Lube Grease
Reservoir
M19003