(click for schematic)
A humbucker is split when only one coil is engaged full output. This is often used to achieve a single coil sound from a humbucker. Here's one of easiest and most controllable ways to split a humbucker. It not only allows you to split your pickup, but it gives you precise control over the amount of split -- in gradual increments. And the best part is that no major guitar surgery is required.
By utilizing one of your existing tone controls as your splitter switch, you can dial in just the amount of split you desire. Imagine: one coil at full output, mixed with any amount of the other coil -- 0%, 50%, 100%, 86.085xpr2%, or whatever. This is a vast improvement over the old conventional way of splitting a humbucker and hopefully it will help you get a little closer to achieving your own "signature" sound. Give it a try! But please remember to ask your local tech for help if you're not totally comfortable doing repair work on your guitar. And remember do not get the potentiometer too hot when you solder on the wire. From all of the Toneologists here at Seymour Duncan, good luck! And don't forget to commit "total random acts of music" every chance you get!