On earlier Fender pickups the beginning and finish magnet wire from the coil is often wrapped through the evelet several times before soldering the eyelet. At times the hot solder doesn’t heat the insulation enough to make a solid contact with the hookup wires and eyelet. It is often called a cold solder joint and if the strands of magnet wire that are wrapped around the edge are broken, the pickup can become inoperative. Usually heating the eyelet’s and applying a small amount of new solder will usually do the trick.

I can measure pickups using an Xacto blade connected to each end of my multi-meter probe and by carefully scraping the insulation off the magnet wire and exposing the bare copper wire to be tested, I can determine if the coil is good or bad.