10” x 30” lathe master electrical problem

I was thinking my mystery line is coming from neutral, so I was thinking it had to tie back into the drum swt in order to complete the loop.
 
No, because the COM terminal of switch 2 comes from neutral according to your sketch so that wouldn't make sense.
I'm a little confused here. How were you turning the machine on and off? By means of the drum switch? Or by switch 1?

I can't tell you where the mystery wire goes because I don't know the terminal arrangement of the relay. That may require some detective work on your part. I'm also not real clear on the pinout of the drum switch as far as the relay coil switching goes. We really need the truth table for both the relay and the drum switch then we could get somewhere; you would need to label the wires, pull them all off, and then use the ohmmeter to id the terminals. It's a time consuming job but it's the sure-fire way to do it.
M
 
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I found this diagram on Ebay but I don't know if it matches your switch:
I've seen two different styles
289909
"X" means connect
 
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That looks like it, except there is no connection on 10 and 8 is connected not 6. 5 is connect to black on the motor. I thought the relay was there as a momentary switch for the start capacitor?
 
See if you can find one of the Grizzly lathes that's similar to yours and has a rotary switch- they have wiring diagrams in their manuals
 
I have been looking all morning I need find out what that relay is, I think it is an overload relay, but it doesn't seem wired correctly. At this point I am just trying to find a good working schematic and change all of it for simplification. The push button switch is not need as I do not have a cover door. The safety off switch I would like to relocate near my knee so if my hands where to get caught up in the machine, I can use my knee to shut it down.
I believe the overload relay is needed for the start capacitor. My knowledge of motors is in low voltage motors not AC, so I am trying to teach myself knew things here.
Here are some overload relay schematics

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Apparently you have a single capacitor motor, all the new Grizzly lathes in that size range have dual capacitor motors and a different relay system.
The third picture you posted there in #19 I believe represents how your machine should be wired, except your relay is 3 pole not 4. Two poles are for power and the third would be for the latching function.
The relay should close and latch when the motor runs. The motor has a centrifugal switch inside which drops out the start cap when it gets up to speed.
The relay should drop out if any of the following happens:
1)The guard switch(s) opens
2)The rotary switch is moved
3) Stop button pushed

Does your machine have/had a push to start switch? For all the above to work it requires a momentary start power switch, normally open
 
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