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SERVICING
Emerson UltraCheck-EZ™ Diagnostic Tool
The Emerson UltraCheck-EZ™ diagnostic tool may be used to
diagnose the ECM motor.
WARNING
HIGH VOLTAGE
Disconnect ALL power before servicing or installing
this unit. Multiple power sources may be present.
Failure to do so may cause property damage, personal
injury or death.
To use the diagnostic tool, perform the following steps:
1. Disconnect power to the air handler.
2. Disconnect the 4-circuit control harness from the motor.
3. Plug the 4-circuit connector from the diagnostic tool into
the motor control connector.
4. Connect one alligator clip from the diagnostic tool to a
ground source.
5. Connect the other alligator clip to a 24VAC source.
NOTE:
The alligator clips are NOT polarized.
NOTE:
The UltraCheck-EZ™ diagnostic tool is equipped with a
nonreplaceable fuse. Connecting the tool to a source other than
24VAC could damage the tool and cause the fuse to open. Doing
so will render the diagnostic tool inoperable.
6. Turn on power to air handler or modular blower.
WARNING
Line Voltage now present.
7. Depress the orange power button on the diagnostic tool
to send a run signal to the motor. Allow up to 5 seconds
for the motor to start.
NOTE:
If the orange power button does not illuminate when
depressed, the tool either has an open fuse or is not properly
connected to a 24VAC source.
8. The green LED on the diagnostic tool will blink indicating
communications between the tool and motor. See table
below for indications of tool indicators and motor actions.
Replace or repair as needed.
Power
Button
Green
LED
Motor
Action
Indication(s)
OFF
OFF
Not
Rotating
Confirm 24VAC to
UltraCheck-EZ
TM
tool.
If 24VAC is confirmed,
diagnostic tool is
inoperable.
ON
Blinking Rotating
Motor and control/end
bell are functioning
properly.
ON
OFF
Rotating Replace motor
control/end bell.
ON
Blinking
Not
Rotating
Check motor (see
Motor Checks
below).
ON
OFF
Not
Rotating
Replace motor
control/end bell; verify
motor (see
Motor
Checks
below).
9. Depress the orange power button to turn off motor.
10. Disconnect power. Disconnect diagnostic tool.
11. Reconnect the 4-wire harness from control board to
motor.
Electrical Checks - High Voltage Power Circuits
WARNING
HIGH VOLTAGE
Disconnect ALL power before servicing or installing
this unit. Multiple power sources may be present.
Failure to do so may cause property damage, personal
injury or death.
1. Disconnect power to air handler or modular blower.
2. Disconnect the 5-circuit power connector to the ECM
motor.
3. Turn on power to air handler or modular.
WARNING
Line Voltage now present.
4. Measure voltage between pins 4 and 5 on the 5-circuit
connector. Measured voltage should be the same as the
supply voltage to the air handler or modular.
