1978/6hp plug wire from power pack

[njmedic3306]

I was replacing the plugs in my 6hp when one of the wires came out from the power pack. I replaced the plug and pushed the wire back into the unit and to my surprise it ran. I have worked on bigger motors and I don't remember the plug wires pulling out of the packs, is this normal? I see in the parts manual it shows it as a sperate part but there was only a bare wire on the other end.

As always thanks for your life (and money) saving help...