NVR_NUF

Thanks for the reply. The switches are all the same, and in the same orientation (On/Off/On text on the left). The wiring Is exactly as shown in below wiring diagram.https://guitarelectronics.com/humbucker-series-off-parallel/As I mentioned, it works with the JB Humbucker and the Hot Rails are essentially humbuckers with the same SD color codes black & white / red & green.It's a complete mystery to me.

I have two Hot Rails and a JB Humbucker. They are wired to three DPDT On/Off/On switches (series/off/parallel) according to the following link.https://guitarelectronics.com/humbucker-series-off-parallel/When I check the resistance at the output jack I get the following values:JB Humbucker: Parallel 4.06kΩ - Series 15.85kΩHot Rail: Parallel 5.26kΩ - Series 0Hot Rail: Parallel 5.33kΩ - Series 0I get nothing when switching the Hot Rails to series, yet it works on the JB Humbucker.Are the Hot Rails wired differently? What am I missing?Thanks everyone for trying to help me.