sears shallow well jet pump mo. 390.25021 pressure switch issues??

Hello.
I am having issues with this well pump, I believe it to be the pressure switch.
How can I test this switch or, test the unit as a whole??
It seems to be overheating, when I run it for a few seconds. all the pump will do is hum at the pressure switch and will cut off unless i unplug it.
It is an old pump, 1974 I believe.

Any help is appreciated. thanks.

You can check the voltage on the two wires going into the motor. Most likely a starting capacitor or the centrifugal switch inside the motor. 36 years? You got your moneys worth out of that one. I would go buy another just like it if you can find one.