I have a folding jobsite table saw with a fancy circuit-breaker type switch on it that will only lock into the on position if it's plugged in to power. However plugging it in and turning the switch to ON yields nothing but the thunk of powered circuit connecting, and again when switching to OFF. I've removed the switch to test it and it has a very cryptic diagram on it. So first off, can someone help me decode this diagram? And secondly, the motor in the saw has 4 wires coming from it, how do I connect that to standard 2 wire 120VAC to test without the switch in the situation, assuming the switch is the problem.

 

You need to find out the nature of the motor, is it a brushed motor with a commutator, Or?

 

I would say power is in on pins 3/7 and when you push the switch it latches using a built in coil on pins 4/8 , if it doesn't latch it might be the internal coil.
You can test the contacts with a multimeter on Ohms, or as a temporary measure link the switch contacts out to see if the saw works.