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QUICK
CHECKS
COMPRESSOR
With cover and board accessed, power off. Discharge capacitor and check resistance across
2 terminals of capacitor. This will measure START and RUN windings of compressor. No need
to remove wires. Check on 200 ohms scale or such. Should read 3 to 10 ohms. Checking from
either wire on terminal of capacitor to the BLACK wire on RY101 will check the overload and
COMMON. Be sure to check each to ground, an open circuit should be seen at each terminal.
If no shorts or grounds appear on compressor windings, remove BLACK and GREY wire from
on RY101. Safely jump the BLACK and GREY wires. Re-apply power and ONLY the compressor
should run.
FAN MOTORS
Measure the DC voltage from black to red leads, for either fan at the following pins: ID fan
connector CN103 1-6 OD fan connector CN102 1-5 DC voltage should be (line voltage x 1.4)
290-390 vdc
No voltage, check FU102 for open or replace drive board.
Check motor resistance black to red in both polarities:
OL in one direction and 13-15 megohm in the opposite direction. Incorrect resistance, replace
motor and drive board.
THERMISTORS
Unplug CN1 from the main board. Read between pins 1 and 2 for the ROOM THERMISTOR, pins
3 and 4 for the INDOOR COIL THERMISTOR, pins 5 and 6 for the OUTDOOR COIL and between
pins 7 and 8 for the OUTDDOR AIR. Compare to resistance chart on mini-manual.
HEATERS
The individual HEATERS in the heater assembly can be checked by disconnecting the six pin
heater connector plug and reading the resistance to the heater between pins 1 and 4, 2 and 5
and 3 and 6. Compare to resistance chart on Mini-manual.
The THERMAL FUSE and PROTECTOR can be checked by disconnecting the 2 wire (red &
blue wires) connector to the heater assembly. Check resistance between pins 1 and 2 to the
heater. Should read zero ohms with both components intact. A reading of in
fi
nite ohms would
indicate either an open fuse or protector.
