Cessna 1969-1976 172 Series Service Manual page 173

11- 69. TROUBLE SHOOTING
TROUBLE
STARTER WILL NOT OPERATE
STARTER MOTOR RUNS, BUT
I
DOES NOT TURN CRANK-
SHAFT.
STARTER MOTOR DRAGS.
I
STARTER EXCESSIVELY
NOISY.
PROBABLE CAUSE
Defective master switch o r
circuit.
Defective starter switch or
switch circuit.
Defective starter motor.
Defective Bendix drive.
Damaged starter pinion
gear or ring gear.
Low battery.
Starter switch or relay contacts
burned
o r dirty.
Defective starter motor
power cable.
Loose or dirty connections.
Defective starter motor.
Dirty or worn commutator.
Worn starter pinion gear or
broken teeth on ring gear.
REMEDY
Check continuity of master
switch and circuit.
Install new switch
or
wires.
Check continuity of switch
and circuit.
Install new switch o r wires.
Check voltage to starter.
If voltage is present.
Remove, repair
or
install
new starter motor.
Remove starter and inspect
Bendix drive.
Replace defective parts.
Inspect starter pinion gear
and ring gear. Replace
defective parts.
Check battery.
Charge o r install new battery.
Install serviceable unit.
Inspect cable.
Install new cable.
Inspect connections.
Remove, clean and tighten all
terminal connections.
Check starter motor brushes,
brush spring tension, thrown
solder on brush cover. Repair
or install new starter motor.
Inspect commutator.
Clean and turn commutator.
Inspect starter pinion gear and
ring gear. Replace defective
parts.
11-70. PRIMARY MAINTENANCE. The starting cir-
Inspect the battery and wiring. Check battery for
cuit should be inspected at regular intervals, the f r e -
quency of which should be determined by the service
and conditions under which the equipment is operated.
fully charged condition, proper electrolyte level with
approved water and terminals for cleanliness. In-
spect wiring to be sure that all connections a r e clean
Change 3 11-23