Carrier 38MBR series Service Manual page 26

DIAGNOSIS AND SOLUTION (CONT)
Index 1
Indoor or Outdoor DC Fan Motor (control chip is in the fan motor). Power on and when the unit is in standby, measure the voltage of pin−1
− pin3, pin4 −pin3 in the fan motor connector. If the value of the voltage is not in the range showing in the table below, the PCB has an issue
and needs to be replaced.
No.
1
2
3
4
5
6
Fig. 18 – Control Chip
Table 16—DC motor voltage input and output
COLOR
Red
---
Black
White
Yellow
Blue
26
SIGNAL
Vs/Vm
---
GND
Vcc
Vsp
FG
VOLTAGE
200~380V
---
OV
13.5~16.5V
0~6.5V
13.5~16.5V