The following wiring diagram applies for Humbucker Pickup. Herein you will find brief description of what a humbucker is, pickup position, four-conductor wiring, Humbucker wiring color codes, standard humbucking operation, coil splitting, parallel wiring, out of phase wiring, how to install a pickup, pickup height adjustment, parts suppliers, additional wiring diagrams and hook-up detail for 4 conductor pickup.
A humbucker is a pickup design consisting of two coils, which are connected electronically out of phase and with opposite magnetic polarities. The effect of this design is to cancel hum and other extraneous noise. The main difference between bridge and neck/middle pickups is output. There is naturally less string vibration closer to the bridge, so bridge pickups are generally wound hotter than neck/middle pickups to compensate for this. Calibrating the pickups this way allows for a more even output balance between the neck and bridge positions.
Find detail of Humbucker Pickup Wiring Diagram (source: www.sixstringzone.com)