Getting Nxt motor to run with arduino and motor shield

I have a NXT motor hooked up to my arduino and motor shield, and can feel it vibrating as though it has power. Yet when I try to run the code I have it does nothing.

What code? What motor shield? How do you have it hooked up? Schematic? Power source?

The code is a sample of how to run a DC motor:

void setup() {
  
  //Setup Channel A
  pinMode(12, OUTPUT); //Initiates Motor Channel A pin
  pinMode(9, OUTPUT); //Initiates Brake Channel A pin
  
}

void loop(){
  
  //forward @ full speed
  digitalWrite(12, HIGH); //Establishes forward direction of Channel A
  digitalWrite(9, LOW);   //Disengage the Brake for Channel A
  analogWrite(3, 255);   //Spins the motor on Channel A at full speed
  
  delay(3000);
  
  digitalWrite(9, HIGH); //Eengage the Brake for Channel A

  delay(1000);
  
  //backward @ half speed
  digitalWrite(12, LOW); //Establishes backward direction of Channel A
  digitalWrite(9, LOW);   //Disengage the Brake for Channel A
  analogWrite(3, 123);   //Spins the motor on Channel A at half speed
  
  delay(3000);
  
  digitalWrite(9, HIGH); //Eengage the Brake for Channel A
  
  delay(1000);
  
}

This is the location that I got it from: http://www.instructables.com/id/Arduino-Motor-Shield-Tutorial/?ALLSTEPS
It is the motor shield V2.0 from Seeed studios. Motor Shield V2.0 - Seeed Wiki
The motor is a NXT motor and I striped the wire and inserted the ones that deal with powering it(white positive, black ground) into the motor interface slots on the motor shield, as shown on the schematic on the wiki, as apparently the images my phone takes are to large to put even one.
The power source is a 9V battery plugged into the external power jack on the motor shield, though I believe that either the battery holder or where it is connected may be the problem as the arduino has to be pluged into the usb to have power yet the battery itself passes the tongue test.
EDIT: remembered multi-meters exist, tested the connections, it was a bad connection at the 9Vbattery holder. It works now.

9V battery - there's your problem I think. They cannot power even pretty tiny motors.