Спасибо!
Там еще тонкости есть - надо определить, одинаковой ли полярности синглы:
"Usually, the pickup that is RWRP (обратной полярности) has a different color hot lead. The RWRP pickup may have yellow and black leads, as opposed to white and black. But even if they all come with the same color leads, telling them apart is a piece of cake.
Take two pickups, and put them together, face to face. If they repel each other, they have the same polarity, so the pickup you did not select is the one that has reverse magnetic polarity.
If the two pickups attract each other, one is north, and one is south. Put one pickup aside, and try the same test with the other two pickups. If they repel each other, the pickup you put aside has reverse magnetic polarity. If they attract, the pickup you are still holding from the first test has reverse magnetic polarity"