TM9-2320-363-20-1
Table 3-1.
Troubleshooting
(Cont)
Malfunction
Test or Inspection
Corrective Action
ELECTRICAL SYSTEM (CONT)
Engine Brake Retard Circuits (Cent)
2.
ENGINE
BRAKE
RETARD
(JAKE
BRAKE)
TWO-CYLINDER
BRAKE
NOT
OPERATING,
FOUR-CYLINDER
BRAKE
OPERATING
NORMALLY.
Step 1.
Step 2.
Step 3.
Step 4.
3.
ENGINE
BRAKE
TWO-CYLINDER
Step 1.
Step
2.
Step 3.
Disconnect
lead 121 C from two-cylinder
brake switch. Check
for +12
VDC
at
two-cylinder
brake
switch.
.
If +12
VDC
is present,
go to step 2. If no voltage
is present,
replace
two-cylinder
brake switch (pages
4-178,
4-182).
Disconnect
lead 121 C from line disconnect from two-cylinder
brake
switch.
Check
for +12
VDC
at lead
121C.
.
If +12
VDC
is present,
go to step 3. If no voltage
is present,
repair lead
121 C (page 3-2).
Disconnect
lead 121C
from line disconnect to center
cylinders
engine
brake
solenoid
valve.
Check
for +12
VDC
at lead 121C.
.
If +12
VDC
is present,
go to step 4.
If no voltage
is present,
repair lead
121C
(page 3-2).
Check
for continuity
between
contact of center cylinders
engine
brake
solenoid
valve
and ground.
.
If continuity
is indicated,
notify direct support
maintenance.
If
no continuity is indicated,
repair ground
(page
3-2).
RETARD
(JAKE
BRAKE)
FOUR-CYLINDER
BRAKE
NOT
OPERATING,
BRAKE
OPERATING
NORMALLY.
Disconnect
lead
121B from four-cylinder
brake switch.
Check
for +12
VDC
at
lead
121 B to four-cylinder
brake switch.
.
If +12
VDC
is present,
go to step 2. If no voltage
is present,
repair lead 121 B (page 3-2).
Disconnect
lead 121D
from four-cylinder
brake switch. Check
for +12 VDC
at
lead
121 D to four-cylinder
brake switch.
.
If +12
VDC
is present,
go to step 3. If no voltage
is
repair lead
121D
(page 3-2).
Disconnect
lead 121D
from line disconnect from two-cylinder
brake
Check
for +12
VDC
at lead
121D.
.
If +12
VDC
is present,
go to step 4.
If no voltage
is
repair lead
121D
(page 3-2).
present,
switch.
present,
3-26
