Help! Pool motor starts intemittently

Hope someone can help me with a real head-scratcher. I've had a swimming pool with a 1/12 horsepower motor for 15+ years. I've replaced motor a few times without incident. Earlier this year, I turned it off to clean and it wouldn't turn back on. Replaced motor twice; same problem. Some times it starts, some time it doesn't. Even when it doesn't start, basic electric meter shows current reaching the motor. I'm stumped. Any ideas?

Where is it switched? Sounds like there might be a short somewhere in the supply line/switch/subpanel. If it is switched near the pump, try replacing the switch (after isolating it at the panel) preferably with a double-pole switch, assuming 230v. If the wiring is old/perished, that could be suspect too, especially if it is not armored or uv resistant.

Pete