Dimarzio pickup has sound despite not being fully connected

[Bowtomecha]

I have a dimarzio fast track 1 single coil sized rail pickup in the neck position of my guitar. I’ve been using sleeved alligator leads to test out the coils in series, parallel, and independent coils while plugged into my amp. I’ve noticed that when I have just the conductor shielding grounded and any of the 4 colored wires hot, I get a sound when I play the strings. It’s much lower in volume than any start and finish on a coil when they are grounded and hot. Also when I have the pickup wired to either coil, and I lightly tap either rail with a screwdriver, I get a metal to pole piece sound no matter which coil I’ve isolated.

I have the model with the quick connect at the bottom. It is direct mounted in a shielding painted cavity although it’s doesn’t seem to be touching I believe..but the rail bottoms are more exposed on the modern versions so I’m not sure if that’s an issue.

Is this just typical of this style of pickup? Also I noticed that I can’t seem to get the cover off. I didn’t seriously try in case I’m supposed to return it and I didn’t want to mess anything up. But I noticed that with the headstock pointing upright at the ceiling, the dimarzio logo is properly displayed and the cable is connected towards the controls as expected. But checking the polarity of the fast track, it seems that the coil towards the neck is North and the one towards the bridge is South.

I checked the resistance as:
Green white = 3.62k
Black red = 2.30k
Series = 5.92k
Parallel = 1.41k

So what gives exactly? The coils seem within range but they also pick up the strings being played when the coils aren’t wired to ground, just the shielding. Not to mention, it doesn’t sound hardly single coilish like the fast track 1 should I suppose. If there was a short, wouldn’t it show at a much different resistance? Or is this just how these pickups are and I never noticed?I could swear the ft1 sounded a lot more wiry. I have about ten days to exchange it but I’m holding out for suggestions on what this is and if I can correct it.

 

[freefrog]

Not enough time to read your post extensively / in details but...

-when you touch the magnetic pole(s) of a disabled coil, it excites the magnet and the magnet excites the enabled coil through the other magnetic pole(s). No surprise there.

-with 4 conductors wiring, "capacitive coupling" is always possible: wires being pressed next to each others they develop a parasitic capacitance and it's as if each wire was connected to the other(s) through some low value capacitors. It causes some bleeding that many people don't notice... until they do. ;-)
It's more or less noticeable according to the actual physical specs of transducers. It can be annoying. But it's not a flaw: rather a downside of how such pickups are wired.

 

[Spaghetti Bolo]

Blackout/EMG pickups have the coils connected straight to the internal preamp. They are unconnected to the output line. However they will still give out some signal even with no battery, due to coupling through the PCB.

 

[Artie]

The primary and secondary coils of a transformer have no physical connection. But they pass voltage and current just fine. A pickup is the secondary coil of a transformer. It can still pass a signal while being mal-connected.