I am using the Arduino to PWM a signal to an LMD18200 (analogWrite(PIN, 100)). My motor is just sitting there ‘stuck’ (I can hear it trying to go) - like it is not getting enough current. So I hooked up my volt meter to check the current draw and BLAMO - the motor starting working. I hook the motor right up to the output of the LMD18200, it does not work, I put my volt meter in, and it works fine. What gives? Any thoughts? This is completely perplexing me.

check your connections for continuity. maybe you have a high resistance connection between wherever you are connecting your voltmeter.