Basically either the pickup coil is continuous or it is not. So measure the resistance between the pins of the connector. It should be a number, not infinity.

The two pin connector of the pickup coil can be a spot for corrosion to interrupt the circuit. In other words, clean it and clean it again. I replaced the pickup coil because I didn't clean it and it tested open. After the new coil was in, I rechecked the original and it was OK, just needed cleaning. Doh!!

R.