The pickup has 2 coil and if it has 4 wires two of them are from one coil, others from the other coil
if you has a pickup with 4 wire you can cabling it in series or parallel
Look at this video
I have a newer Ray4 with the same pre of Ray24ca and a 4 wire plus shield pickup.
the wire are white, black, red and green
Do you knows the hot and the cold wires?
thanks