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CBX32MV
INDOOR BLOWER MOTOR (B3) CONTROL
TROUBLESHOOTING (EMERSON)
1.
Disconnect three-wire harness from motor control
module.
A
If the plug terminals inside the module are
damaged.
B
If terminals are not damaged, proceed to next step.
2.
Inspect the negative temperature coefficient (NTC)
thermistor (see figure 33) for any cracks or breakage.
A
If damaged, replace control
.
B
If no damage is detected, proceed to next step.
3.
Check the capacitors for any damage. Inspect for:
A
Bulging or swelling caps. If caps are bulging or
swollen, replace control.
B
If no damage is detected, proceed to next step.
4.
Check resistance between each of the three pins on the
control module jack (see figure 33). Resistance
between any two terminals should be greater than 100
K ohms.
A
If resistance is less than 100 K ohms, replace
control.
B
If no damage is detected, proceed to next step
.
NOTE -
If your ohm meter is not an auto-ranging type,
please set it to the highest ohm scale (100 K ohms or
greater).
Scale
Measurement range in
words
ohms
2 M
two megohm-two million
ohms
0 - 2,000,000
200 K
two hundred kilo-ohm-two
hundred thousand ohms
0 - 200,000
20 K
twenty kilo-ohm-twenty
thousand ohms
0 - 20,000
2 K
two kilo-ohm two-thousand
ohms
0 - 2,000
200
two hundred ohms
0 - 200
Figure 32. Typical Digital Multimeter
CONTROL MODULE
3-PIN JACK
NTC
THERMISTOR
Figure 33. Module Test (Emerson(
Additional Indoor Blower Motor (B3)
Troubleshooting
1.
If motor shaft spins freely in both directions, proceed to
next step. If not, replace motor.
2.
Check the motor to control harness for any damage.
A
If harness or terminals are damaged replace the
motor.
B
If there is no damage, proceed to next step.
3.
Check resistance between each of the three-phase
terminals in the motor harness as illustrated in figure
34. Resistance between any two contacts should be
equal. If resistance between any two contacts are not
equal, or if any resistance shows open or
short-circuited, replace the motor.
MOTOR 3-PIN
PLUG
Figure 34. Motor Test (Emerson)
