If you can meg the motor and work back, and everything is fine, Probably have a control issue.
The vast majority of motor failures we encounter with older motors is the insulation on the windings break down. It will still run, but not right.
Don't know exactly what your motor is. Capacitor start, induction run? If that's the case and you have a bad cap, it won't start. If it's a capacitor start, capacitor run, then the run capacitor may be the devil.
Sometimes we'll see wire as being an issue. It also breaks down over time. You'll get a higher voltage drop to the motor from the source, so the motor isn't seeing what it really needs. 1100 feet of old wire is a good candidate for this issue.
You can have motors rewound to make work somewhat decent again, but it will never work like a new motor.
Last edited by JKB; 09/27/14 09:42 PM.
