The Guitar Wiring Blog is an old established site where I picked lots of diagram when I started modifying guitars.
I’ve made a diagram that shows how 4-wire guitar pickup (Humbuckers) are configured. It can help you understand how many types of Guitar P-Up Wiring (like coil split, series, parallel) works.
As you can see, a humbucker is a guitar pickup made up of two coils. It’s basically like two single-coil P-ups on a plate in series, out of phase with reverse polarity (north / south). Sometimes they share a magnetic bar, sometimes they have independent magnets.
All guitar pickup wire fun is based on changing their relationships. The examples in the illustration show two basic, popular methods of wiring 4-wire humbuckers. The first example shows typical HB cabling. The second shows the split-coil system.
As you can see, the split humbucker configuration is based on a work coil with the hot wire. The second is connected to earth via both wires. This coil doesn’t work like a pickup, but is part of the guitar wiring ground. So a humbucker can work like a single coil guitar pup.
Coils for HB usually differ from coils for classic SCs. Because of this, you likely won’t get the true Strat guitar tone with a split humb. It doesn’t mean you’re getting the worst of sounds. It means that I am writing over two, slightly different types of tones.
By the way, be sure to check your humbucker wire color code before you start making any guitar wiring. You can find it on the manufacturer’s website or Here