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Components
Checklist
DC motor 1. Remove the motor cover, and measure resistance at the following points to check for coil
breakage:
(Measure the resistance with the motor connectors (CN9, CN10) disconnected from the
power circuit board.)
<VL-250 type>
• Between V and U...102.8 Ω
• Between V and W...102.8 Ω
• Between W and U...102.8 Ω
<VL-350 type, VL-500 type>
• Between V and U...27.8 Ω
• Between V and W...27.8 Ω
• Between W and U...27.8 Ω
* Resistance in a 30 °C atmosphere
2. Other check points
• Are any parts discolored to black?
• Is any liquid adhered to any parts?
• Is the circuit board broken?
• Is the solder cracked?
[4] Diagnosis of the thermistor
Remove the thermistor connector (RA thermistor: CN15, OA thermistor: CN22) from the control circuit
board, and measure resistance to detect a failure.
Resistance (reference)
Reference temperature
for failure detection
Open (100 kΩ or higher)
It is abnormal.
Shorted (1.0 kΩ or lower)
It is abnormal.
3.0 kΩ
30°C
4.2 kΩ
20°C
6.0 kΩ
10°C
8.8 kΩ
0°C
20.6 kΩ
-10°C
32.8 kΩ
-20°C
53.9 kΩ
-30°C
U
<Circuit board in the DC motor for VL-250 type>
V
W
U
<Circuit board in the DC motor for
VL-350 type and VL-500 type>
V
W
