Komatsu 830E Shop Manual page 594

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
enable the shutters for cold weather operation or to dis-
able the shutters during warm weather.
Note: Refer to the electrical schematic in Figure 19-3
for the following component descriptions.
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
coolant temperature is low.
Komatsu SSDA16V1610 Engine:
If equipped with the Komatsu engine, the ECM will pro-
vide a +24VDC signal (circuit 65S) to energize relay K5
located on relay board #6. 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 enable switch (closed for shutter operation)
and will energize the shutter solenoid valve to direct oil
to the head end of the shutter actuator cylinder to close
the shutters.
After the coolant has reached the proper operating
temperature, the ECM will remove the +24VDC to the
K5 relay coil and it will de-energize, opening the N.O.
contacts and removing +24VDC from the shutter sole-
noid circuit, directing oil to the rod end of the cylinder to
open the shutters.
MTU/DDEC Engine:
If the MTU/DDEC engine is installed, the ECM will pro-
vide a ground path to energize relay K5 on relay board
#6 to energize it and close the N.O. contacts to provide
+24VDC from relay K3 to the shutter control solenoid
when the key switch is ON and the shutter enable
switch is closed.
After the coolant temperature has reached the proper
operating temperature, the ECM will open the ground
circuit (563M) and de-energize relay K5 opening the
N.O. contacts and removing +24VDC from the shutter
solenoid circuit, directing oil to the rod end of the cylin-
der to open the shutters.
Both Engine Installations:
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.
M19-2
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 #6, located in the electrical cabinet. Its
location may vary depending on the engine installed,
options installed, and the date the truck was manufac-
tured. The example in Figure 19-3 shows relay board
#6 located on the left wall of the right compartment.
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
M19002