Service manual

Electrical System
10-85
Model 3606 • Origin 10/99
7. LOSS OF ELECTRICAL
POWER for some but not all
vehicle operations.
1. No voltage at these circuits,
caused by a broken wire or switch,
or a blown fuse.
1. Repair wiring, switch and fuse as
required.
8. FUSE continuously blows. 1. Check the system for shorts, loose
grounds, defective or corroded
electrical components.
1. Repair or replace as required.
9. Overheating and burnout of
wiring and electrical com-
ponents.
1. Incorrect fuse for circuit or fuse is
bypassed with a jumper.
IMPORTANT: NEVER connect a
jumper between fuse terminals with-
out providing an equivalent protective
device in the jumper.
1. Use correct fuse. Correct the
cause of the overload and
replace damaged wiring,
components and fuses as
required.
10. Starting System/GENERAL
Engine will not crank and
starter relay or starter sole-
noid does not engage.
Note: Refer to the Perkins or
Cummins engine troubleshooting
information in
Section 8A
or
Section 8B
.
1. Transmission is in FORWARD (F)
or REVERSE (R).
2. Battery is discharged.
3. Inoperative ignition switch, relay or
solenoid.
4. Starting circuit is open or has high
resistance.
5. Neutral relay is open or shorted.
1. Shift travel select lever into
NEUTRAL (N).
2. Check battery and charge or
replace battery.
3. Check circuitry and repair or
replace faulty components.
4. Check circuit connections and
repair or replace faulty wiring.
5. Check and replace as necessary.
11. Starter relay closes and
solenoid engages but
engine will not crank.
1. Battery is discharged.
2. Defective starter motor
connections or loose battery
connections.
3. Starter motor is faulty.
4. Relay or solenoid contacts are
burned.
5. Engine is seized, crankshaft
cannot rotate.
1. Check battery and charge or
replace.
2. Check, clean and tighten
connections.
3. Inspect, repair or replace.
4. Replace relay or solenoid.
5. Repair or replace engine or
transmission as required.
12. Starting motor turns but
does not crank engine.
1. Defective starter solenoid or
pinion.
2. Defective solenoid or pinion drive.
3. Defective flywheel ring gear.
1. Inspect and repair or replace.
2. Inspect and repair or replace.
3. Inspect and replace.
13. Engine cranks slowly. 1. Battery output is low.
2. Excessive resistance in the
starting circuit.
3. Defective starter motor.
1. Check battery and charge or
replace.
2. Check circuit connections and
repair or replace faulty wiring.
3. Inspect and repair or renew.
Electrical System Troubleshooting
Problem Possible Cause Remedy