Carrier 42LUVH045N - Key Component Resistance Checks

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9.2.3 E2(zero-crossing signal error) diagnosis and solution
9.2.4 E3(indoor fan speed out of control) diagnosis and solution
9.2.5 E5(Open or short circuit of outdoor temperature sensor) diagnosis and solution.
Is the outdoor
temperature sensor
connector and
connection good?
Repair the connector
and reconnect
Replace the sensor
and check if E5
display again?
NO
YES
Replace outdoor
e-box
YES
Is the indoor fan
motor connector and
connection good?
Repair the connector
and reconnect
Is voltage being
applied to the fan
motor?
(rang 90v-160v
between mid pin and
N on CN1
NO
YES
Indoor PCB is
defective. Replace the
indoor PCB.
YES
Replace the indoor fan
motor
NO
Is power supply and
connection of
connectors good?
Indoor PCB is defective.
Replace the indoor PCB.
Be sure the power supply
is good and correct the
connection
NO
YES