ohh no, what have I done to my pump??

I have a Waterway brand sandfilter on a 1.5HP pump. Because of a recent divorce, I haven't had the extra money to pay for a permanent electrical connection to the pump, so I've been using a heavy-duty extension cord connected to a GFCI breaker. No problems with it at all.

I have been in the process of winterizing my pool and had the pool vac running for about 3 hours, no problems. Disconnected the plug, removed the vac and plugged pump back in and nada. It won't work.

I have checked the extension cord, the outlet, the breaker box, etc and everything is in working order. Other appliances connected to my set up work, so it has to be the pump.

What am I missing? Is there a fuse in the pump that I've possibly blown? The system isn't even a year old :(

I'm assuming the pump has a short cord on it with a plug into the extension cord. Is there any sign of overheating looking at the prongs of the plug or the plug itself? My next suggestion would be to go right to the terminal block at the back of the motor and check voltage there. Is it a 120 or 240 volt motor? Reason I ask is if it is 120 then you're pulling probably 15+ amps for that size motor. At currents like that it increases the chance of just blowing a wire at the plug. Once you get a connection going bad the heat builds up, resistance goes up, more heat, vicious cycle leading to a wire blowing apart. I seriously doubt you damaged the motor itself.
Al