KNOWN INFO
POSSIBLE PROBLEMS
DIAGNOSTIC FLOWCHART
TEST OPTIONS
REASON FOR QUESTION
KNOWN INFO
POSSIBLE PROBLEMS
NO
YES
2-170 Change 1
ENGINE COOLING
DISCONNECT THE CONTROL
VALVE ELECTRICAL
CONNECTOR AT THE TIME DELAY
MODULE. DOES THE FAN
ENGAGE?
B
FROM A4, Page 2-166
REPLACE CONTROL
VALVE
B1
B2
FAN DRIVE OK
FAN DOESN'T ENGAGE
VIA WIRE 458
FAN WIRING
TIME DELAY MODULE
FAN CONTROL VALVE
PCB/DISTRIBUTION BOX
TRY IT.
With no power to the solenoid,
the fan should engage.
FAN ENGAGES
CONTROL VALVE OK
WIRING
TEST OPTIONS
REASON FOR QUESTION
NO
YES
KNOWN INFO
POSSIBLE PROBLEMS
B3
FAN ENGAGES
CONTROL VALVE OK
WIRING
TEST OPTIONS
REASON FOR QUESTION
NO
YES
DISCONNECT THE 4-WIRE
CONNECTOR AT THE TIME DELAY
MODULE. IS THERE CONTINUITY
FROM 458B AT THE 4-WIRE
HARNESS TO 458B AT THE
FAN TEMPERATURE SWITCH?
REPAIR/REPLACE
WIRE 458B
1. STE/ICE-R TEST 91 (Page 2-752)
2. MULTIMETER
Wire 458B connects the switch
and the timer.
GO TO B4,
Page 2-172
WITH THE ROTARY SWITCH ON
"RUN," IS THERE BATTERY
VOLTAGE AT THE HARNESS SIDE
OF WIRE 583B IN THE 4-WAY
CONNECTOR OF THE TIME DELAY
MODULE?
REPAIR/REPLACE
WIRE 583B
1. STE/ICE-R TEST 89 (Page 2-750)
2. MULTIMETER
Wire 583B connects battery
voltage to the delay module.
TM 9-2320-280-20-1
