Graco Ultra MAX II 490 PC Pro Operation, Parts page 33

Problem
3A6491E
What to Check
Troubleshooting
How to check
5.Perform Spin Test: Test at large
4-pin motor field connector.
Disconnect fluid pump from
sprayer. Test motor by placing a
jumper across pins 1 & 2. Rotate
motor fan at about 2 revolutions per
second. A cogging resistance to
motion should be felt at the fan.
The motor should be replaced if no
resistance is felt. Repeat for pin
combinations 1 & 3 and 2 & 3. Pin 4
(the green wire) is not used in this
test. If all spin test is positive,
continue to step 6.
GRN BLU R BLK
STEP 1:
GRN BLU R BLK
STEP 2:
GRN BLU R BLK
STEP 3:
6.Perform Field Short Test: Test at
large 4-pin motor field connector.
There should not be continuity from
pin 4, the ground wire, and any of
the remaining 3 pins. If motor field
connector tests fail, replace motor.
7.Reconnect motor connector(s) to
control board socket(s). Connect
power, turn ON/OFF switch ON and
control knob to 1/2 turn clockwise. If
motor does not run, replace control
board.
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