Electrical polarity and certain "mixed" pickups presenting as dead when +/- reversed

[kayakerca]

A luthier acquaintance asked me a question today to which I had no idea of the answer. I said I would put the question forward here to see if anyone has had similar experiences and/or an understanding of the issue/problem. So here comes his question:

"I have to ask a pickup expert because I just can't explain this little issue I've been running into with strat and tele pickups. I've seen the issue I'm about to describe only on Van Zandt and Fender single coils.

When installing different pickups brands in a guitar, you sometimes have an out of phase problem, where the original pickups are in the opposite phase of the new one. I can tell you that Seymour pickups are always out of phase with fender pickups if you wire them in the usual way. The solution is simply to swap the + and the - leads. You already know this, I know. Here's the weird part: If I switch the + and - on SD pickups, everything works fine, but if I switch the leads on a Fender, or Van Zandt pickup, I get no output what so ever. Nothing, zilch, bupkiss, not a sound, not hiss, nothing, it's as if I unplugged the guitar. How can a strat pickup with two leads work in one direction, but not the other???"

Thanks in advance for responses as to the nature of the problem.

[Stratz]

The only way I can see that happening is if one of the pickups has shorted magnet wire to one of the poles.

The same type of effect can happen when a grounded guitar string (usually via the bridge/claw ground wire) touches a pickup pole that has the magnet wire shorted to it. This will cause the pickup to cut out just as if it were a kill switch.

Perhaps the tech should test the pickups in question for shorts from the rod magnets to the hook up wires.

[verhoevenc]

My first thought is that these pickups have some sort of cover (like tele neck) or plate (tele bridge) that the ground is grounded to and it's only a 2-wire conductor. IE: Switching the wires does you no good as everything will go to ground no matter what. You need to remove the ground from the cover/plate and run it to ground separately via a 3-wire cable. You often also see this when using P90s in a 5-way switch where one position is OOP.
Chris

[big_teee]

I agree with Chris.
The start lead is probably tied to a common ground.
On a Tele bridge pickup, if the start lead is tied to the base plate?
The ground would have to be taken loose from the base plate before you could switch the polarity at the switch.
That is why I always encourage buying a whole set of pickups.
That is the only way the Pickup winder can control Polarity.

[kayakerca]

Thanks Stratz, Chris, Terry. I've passed along your comments. If anything else comes to mind, please pop it into the thread.

[David Schwab]

I can tell you that Seymour pickups are always out of phase with fender pickups if you wire them in the usual way.

That's interesting. I never experienced this.

[kayakerca]

I can tell you that Seymour pickups are always out of phase with fender pickups if you wire them in the usual way.
That's interesting. I never experienced this.

That's interesting. I never experienced this.

In fairness to the top quote, that wasn't my comment, it was part of my luthier acquaintence's comment excerpted from his question in the OP. OK, I'm confused now.

[verhoevenc]

No need for confusion. Regardless of that comment (which I can't comment on as I haven't mixed the two) I'd say the things pointed out are still your likely culprits.
Chris

[David Schwab]

In fairness to the top quote, that wasn't my comment, it was part of my luthier acquaintence's comment excerpted from his question in the OP. OK, I'm confused now.

Yes, I know you didn't make the comment. I don't think it's correct either.