This sounds easy, but with 4 wires from each humbucker, 6 connection points on the switch and 3 pins on volume pot, there is a big chance of messing up. I have made an attempt to create a schematic here. I can't guarantee the diagram as I haven't tested it but I couldn't find any errors myself.
You never mentioned how you want the humbuckers wired. They can be wired in a zillion ways. The most common is to wire them in series and I will assume this. How do you want this wired when the switch is in the middle position? I assume a connection of the two middle coils as in the figure below.
The LP switch works as in the following figure:
Connecting the wires will lead to a diagram like this:
The colour of the wires coming out of the humbuckers will vary between different brands. I have therefore just marked the wires with + and - in the diagram. You will have to find out witch is witch from the documentation.
I hope this helps.
(Edited by SalemB at 6:35 pm on Mar. 17, 2002)
