When I put my foot down on the momentary on switch, it makes a clicking sound like a circuit has just been made. When I take my foot off the momentary on button it makes another click type sound. TM works great. The variable speed control works, on/off, works, no problems. It only clicks when there is power to the TM. I am concerned that the clicking sound is a circuit breaker or other electrical component on it's way out. TM is about four maybe five year's old. Serial # is: K141MK01042
Thank you for any help sent my way.