Motor testing with Simple Servo Tester


New member
First time builder here. Built Simple Cub in one day. Finally ordered electronics.
These are my steps to connect Simple Servo Tester and battery to confirm correct motor rotation.
1. Connect motor to ESC with 3 black leads.
2. On Simple Servo Tester turn knob fully counter clockwise.
3. Connect battery to ESC using large double connector.
4. Connect 3-lead connector from ESC to OUT side of Simple Servo Tester.
Note: Yellow is signal S position
5. Push Select button to switch Tester to Manual, not Neutral or Automatic.
6. Turn Simple Servo Tester knob clockwise to power motor and test motor rotation direction.
7. Switch black motor leads to change rotation direction.
8. Disconnect battery and Tester

I welcome comments


Site Moderator
Staff member
Good summary, I would add, ALWAYS remove the prop. Different brands of servo testers may very which way the knob is turned for on & off. When the prop is on, it could turn into a bad day very fast. The motor could start at full speed when your not expecting it.

The signal wire is always the lightest color, usually white or yellow. The darkest color is negative, usually black or brown. Red is always positive.
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Site Moderator
Staff member
How are you powering the servo tester? That needs power too...
The servo tester will be powered by the ESC.

All of the positive are connected and all of the negative pins are connected. The tester will not care which side the power is coming from. Likewise on a Rx, all of the positive pins are connected and all of the negative pins are connected. The receiver can be powered by any channel.
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Master member
Never even thought about using a servo tester to test a motor, usually just plug in a receiver to the BEC COOL (y)