Lennox XC17 Series Unit Information page 45

A simple test can be used to test the fan motor operation. A fully charged 9V battery will be required for this procedure.
FAN MOTOR TEST
THIS IS A TEST THAT WILL VERIFY THAT THE MOTOR DOES OPERATE.
1. VERIFY MAIN (240 VOLT) POWER IF OFF TO UNIT.
2. REMOVE BOTH WIRES (BROWN AND BLACK) FROM THE J2 TERMINAL ON THE FAN MOTOR CONTROL
(A177).
3. ROOM THERMOSTAT SHOULD BE IN OFF POSITION (UNIT IN IDLE MODE − NO HEATING OR COOLING
DEMANDS)
4. TURN MAIN POWER (240 VOLT) ON TO UNIT.
5. CONNECT 9 VOLT BATTERY TO FAN MOTOR PLUGS AS NOTED IN PICTURE BELOW.
6. FAN MOTOR SHOULD RUN AT A REDUCED FAN SPEED.
7. IF FAN MOTOR DOES NOT RUN, THEN REPLACE FAN MOTOR ASSEMBLY.
REMOVE BOTH LEADS
FROM J2 TERMINALS
BLACK LEAD
BROWN LEAD
Fan Motor (B4) Test Procedure
FAN MOTOR CONTROL (A177)
J2
J2
CONNECT FAN MOTOR BLACK
COMMON WIRE TO 9V BATTERY
Figure 23. Fan Motor (B4) Test
Page 45
BLACK LEAD
BROWN LEAD
BLACK LEAD
NEGATIVE TERMINAL
NEGATIVE TERMINAL
FULLY CHARGED 9V BATTERY
BROWN LEAD
CONNECT FAN MOTOR WIRE TO
9V BATTERY POSITIVE TERMINAL
V
POSITIVE TERMINAL
XC17