Hi, not sure I can be off too much help, but here goes nothing: I was able to find a website where I could download schematics of old Hammonds, which included the layout of the Leslie hookup. If you still have the jack & plug attached to the end, keep them! According to the schematic, pin 1 & 5 go to the speaker, - & + respectively, pin 2 is the "fast motor" lead, pin 4 the "slow motor", & pin 3 is common return for both. Your best bet would be to look up the schematic to your model, as that layout may be different on some models. I wired mine up with an on/off/on SPDT rocker switch, each "on" to the fast or slow motor with the center to the common ground. I also carefully separated the 120v wiring from the speaker wires, to hopefully idiot-proof it. The speaker is likely a Jensen C8R, which means you want to avoid using any amp over 25w.