Piper Navajo Chieftain PA-31-350 Service Manual page 817

Loose primary connec-
tion at ignition assembly
Faulty vibrator.
Combustion air blower
speed fluctuates. (Can
be caused by low volt-
age. loose blower
wheel. worn brushes
or motor.
NAVAJO CHIEFTAIN SERVICE MANUAL
TABLE
XIII-I. TROUBLESHOOTING
CHART (HEATING
SYSTEM) (cont.)
Remed
Trouble
Cause
Combustion air
blower fails to
run. (cont.)
Heater fires but
burns unsteadily.
Faulty or burned-out
motor.
Insufficient fuel supply.
Remove combustion air
motor for overhaul or
replacement of motor.
Inspect fuel supply to
heater. including shut-
off valve. solenoid
valve. fuel pump and
fuel lines. Make necessary
repairs.
Spark plug partially
fouled.
Replace spark plug.
CAUTION
Do not create spark gap
by holding lead to heater
jacket. Damage to lead
and ignition unit will
result and operator may
receive an electrical shock.
High voltage leak in
lead between ignition
assembly and spark
plug.
4D1
Tighten the connection.
Replace the vibrator.
Remove and overhaul
the combustion air
blower assembly as
required or correct
low voltage condition.
Replace ignition assem-
bly.
HEATING AND VENTILATING Revised: 10/15/82