Midea MEHS-09PSH1 Service Manual page 36

Remark:
Use a multimeter to test the DC voltage
between 2 port and 3 port of outdoor unit.
The red pin of multimeter connects with 2
port while the black pin is for 3 port.
When AC is normal running, the voltage
will move alternately between -25V to
25V.
If the outdoor unit has malfunction, the
voltage will move alternately with positive
value.
While if the indoor unit has malfunction,
the voltage will be a certain value.
Remark:
Use a multimeter to test the resistance
of the reactor which does not connect
with capacitor.
The normal value should be around zero
ohm. Otherwise, the reactor must have
malfunction.