Airless Motor Test - Graco FinishPro 390 Repair Electrical Manual

1. Remove the pump pin and try to run the sprayer.If the motor runs check for locked or frozen pump
or drive train. If sprayer does not run, go to next step.
2. Set sprayer to OFF and disconnect power to sprayer .
3. Disconnect motor connector from control board . Check the motor connector and
control board contacts. They must be clean and secure. Reconnect motor connector
to control board socket(s). Turn the pressure knob clockwise a ½ turn. Try to restart the motor.
If motor does not run follow the steps below.
Use CAUTION not to distort the connectors when inserting the meter probes.
Perform a spin test by connecting a 9 volt
battery or larger to the motor leads.
+
-
9 volt
battery
Step 3
Checking the motors thermal protection.
Meter should read100K
Note: motor should be cooled down.
100 K
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288859 Motor Test
Step 1
+ 5%.
Step 2
Spin the motor while checking.
If a open is found replace the motor.
1-3 ohms
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Step 4
Checking the motor wires for a short.
Put the (+) meter lead on the motor case.
Move the (-) meter lead to each wire.
Meter should read open on all the wires.
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