Lionel KW repair

I just put a new whistle disk/rectifier in my old KW, and some posts,
and two new rollers, when i was putting the main post in i notices
three wires going to it. The main power wire, the whistle wire, and
then the overload lamp wire. Is that supposed to go there? Now the
overload lamp is always on and gets brighter as i increase the volts.
Also i dont know if that is setting something off but i cant get any
trains to run. I get light but no motor, my guess is that that wire
dosent belong there? if any one has a wiring diagram or can pull there
cover off, or just knows i appreciate your help thank you.
Joe