Motor Shield - Function of Shorting Jumper Block

The Hardware setup description for Motor Shield Ver. 1 contains this line:
Supply Power Select Connector: USB/Extern Power can supply for driving the Motor. When connect the connector using a jumper cap, the USB power for the motor shieled.
The sentence structure is unclear. Does this mean that with the shorting block (VCC/5V of J4) in place that motor current is supplied by the 5 Volt USB port? I would assume that with the shorting block removed, motor power would be supplied by whatever power source you have connected to the dual screw terminal block labeled GND VS.
Is my understanding correct?

I know this thread is a couple years old but I was recently searching for answers to this problem and could not find a solution. I have however figured it out. The jumper needs to be REMOVED for external power source to be active. Secondly the polarity of the external power source MUST be correctly connected or the shield will NOT switch to the active source. If you look closely at the shield board you will see the terminals are marked with a + and _, left and right respectively. If these two criteria are met then the motor shield v2.0 will operate as described.

have you managed to get a good gps position with the device ? I get a location, but it’s like a 100km away from where I am ! I don’t know if it’s a bug in the device or just that my GPS signal is too small.

If plug motor shield onto the Arduino UNO/Seeeduino, and connect the connector using a jumper cap(J4), that means the Vcc of motor shield can be provided by the USB power of Arduino or Seeeduino, but if moving out the jumper cap, the Vcc of motor shield only can be powered by the external power of motor shield itself.

Maybe you can remove the motor shield and have a test again to see whether it’s a problem of motor shield.

Maybe you can remove the motor shield and have a test again to see whether it’s a problem of motor shield.