It would all depend...Ok - would I not see the
Voltage change on the meter then when turning the wire speed control ??
Thanks bud - have this bru and will make my way into the iglooIt would all depend...
Your test meter is to all intents and purposes an open circuit. If the controlloer is a cheap circuit, the transistor will just be amplifying a potentiometer and what you will see could be full voltage or a varying voltage with the pot - it depends on the circuit configuration. If it's a PWM circuit, you probably would see nothing unless your meter's got a good frequency response though trying to read the voltage on the equivalent AC range may yield something. To make any meaningful measurements, you do need some sort of load in place.
What you are describing does sound like there is a fault with the transistor's drive circuitry - I'd measure the full voltage across the two outer potentiometer pins then measure the voltage across the middle wiper pin and one of the end pins and make sure that it's varying from 0 to full as the pot is swung from stop to stop.