Often when pickups are shielded, they are wrapped with a foil tape that can cut the insulation on the magnet wire and cause the pickups to short out or fail. The pickups should be carefully insulated with a quality electrical tape and then the shielding foil should be carefully cut so the foil doesn’t come in contact with the beginning or finish wires that are connected to the eyelet’s. If the edge of the shielding foil lie across the two wires connected to the beginning and finish eyelet, a short can occur. If you have no need for reversing the two lead wires with a switch for phasing then the foil shield can be soldered to the ground wire on the pickup. Fender pickups usually connect the black wire to ground.