dimarzio pup wiring query

[jlpineda]

got a guitar w/ a dimarzio paf w/ 4 conductor wiring on the neck.....three of the wires (green, red and black are all grounded to the volume pot and the white one is connected to the pot lug.....i'm wondering if anyone has encountered something like this before ? it seems that this makes the pup run single coil? i do love the tone it gives me and when i switched over to their normal series wiring, the pup became "woofy" sounding, thanks