Spark Plug Sparks, But Motor Does Not Start - Desa B350D Service Manual

H I G H P R E S S U R E P O R T A B L E F O R C E D A I R H E A T E R S E R V I C E M A N U A L
TROUBLESHOOTING — PROBLEM CONDITIONS
OBSERVED PROBLEM

Spark plug sparks, but motor does not start.

POSSIBLE CAUSE
A. Motor protector tripped
B. Fuel pump seized
C. Defective motor
D. Defective relay (if equipped)
E. Defective fan switch
TEST PROCEDURES
A. Motor protector tripped
Depress red motor protector reset button on
top of motor case. This resets the motor
protector for proper operation. Determine
causes for motor protector trips before re-
turning heater to customer.
Figure 16 - Reset Button Location
B. Fuel pump seized
1. Unplug heater.
2. Remove upper shell of heater.
Figure 17 - Rotating Fan by Hand
14
Reset Button
3. Rotate fan by hand to determine if pump
is free to turn.
4. If fan is difficult or impossible to rotate,
loosen clamp which holds fuel pump to
motor. Rotate fan and retighten clamp.
5. If fan is still difficult or impossible to
rotate, replace fuel pump.
C. Defective motor
1. Depress red motor protector reset but-
ton on top of motor case before testing
motor.
2. Unplug heater.
3. Disconnect the red and white motor wires
at their wire connection.
4. Set ohmmeter on the RX1 position.
5. Connect ohmmeter test leads to red and
white motor wire. If the resistance indi-
cated reads 0 ohms or indicates an open
circuit, the motor is defective and must be
replaced. Note: Proper resistance for
motor is 1.0 to 1.5 ohms. Make sure you
properly calibrate ohmmeter before test-
ing motor.
Figure 18 - Testing Motor with Ohmmeter
D. Defective relay (if equipped)
Replace defective relay.
E. Defective fan switch
Follow steps under DEFECTIVE FAN
SWITCH, procedure "D" on page 20.