Troubleshooting; Heating Components - Lennox G71MPP SERIES Unit Information

Troubleshooting

To verify motor operation see steps below:
1− Remove J48 (5 pin power plug) from P48 on the mo-
tor.
2− With the power on at the furnace and door switch de-
pressed, use a test meter to verify 120V between pins
4 and 5 on J48.
3− Reconnect J48 to P48 on the motor.
4− Remove J49 (4 pin low voltage connector) from P49
on the motor.
5− Using test jumpers, apply 24V to pins 3 and 4 on P49
on the motor.
Note: Do not apply 24V to pins 2 and 4 on P49. Doing so
will cause permanent damage to the motor.
6− Motor should run at 75%.
7− Test is complete. Remove jumpers and reconnect
plugs.
Another option is to use the TECMate PRO with the 16 to
4 pin adaptor. The use of the TECMate PRO isolates the
motor from the integrated control. Follow the instructions
provided with the kit. If the motor runs do not replace.
BLOWER B3 HARNESS CONNECTORS
SHAFT
MOTOR with IINTEGRATED
CONTROLLER
P48 5 Pin
P49 4 Pin
1
J48 Connector
installed on motor
P49 4 Pin
24v Transformer
Page 30
P48 5 Pin
P49 4 Pin
2
3
4
J48 Connector
5
120v
240v
0
J49 Connector
FIGURE 10