Whether I trim it up or down, it only works for 4-5 seconds and stops. I can wait about 30 seconds or sometimes longer and it works again for 4-5 seconds. The obvious question...is this a sign that the motor is worn out? I've replaced it a couple times in years past, but it usually just quits working period and has never acted like it is acting now. All other electrical components are working fine and my ground wire for the trim motor is secure. Suggestions?