Komatsu PC88MR-10 Shop Manual page 873

No. Cause
Defective starting
5
switch
Defective electrical
intake air heater (ribbon
6
heater)
(Internal open circuit)
Defective heater relay
7
(Does not turn ON)
(terminal R16A)
Ground fault in wiring
harness
8
(Contact with ground
circuit)
PC88MR-10
Procedure, measuring location, criteria, and remarks
a If no failure is found in primary side by check on Cause 3, this check is not
required.
1. Turn starting switch to OFF position.
2. Turn battery disconnect switch to OFF position.
3. Disconnect connector H15 and connect T-adapter to male side.
4. Turn starting switch to OFF and the HEAT positions to perform
troubleshooting.
Resistance Between H15 (male) (1) and (3)
1. Turn starting switch to OFF position.
2. Disconnect terminal E01.
Continuity Between E01 terminal and ground
If no failure is found by check on Cause 3 and heater relay operation sound is
not heard, heater relay is defective.
a If no failure is found by check on Cause 3, this check is not required.
1. Turn starting switch to OFF position.
2. Disconnect connectors H15, CM01, D02, terminals R15, E01, and F06
terminal of fuse.
Between heater relay terminal R15 (wiring harness
side) and ground
Between heater relay R16B (contact side input
Resistance
terminal) and ground
Between heater terminal E01 (wiring harness side)
and ground
40 Troubleshooting
Troubleshooting of electrical system (E-mode)
OFF
HEAT
Min. 1 Mz
Max. 1 z
Continuity
Min. 1 Mz
Min. 1 Mz
Min. 1 Mz
40-385