Hey fatmunkey,

Here is a post by seymour duncan that explains his mechanism using a switch (or push pull pot) to switch the middle position of the 3-way switch from parallel to serial.

http://www.seymourduncan.com/blog/th...ddle-position/

here's the diagram from the post:

Click image for larger version. 

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For series wiring to be possible, you will need to modify your neck pickup to separate the ground wire attached to the pickups chassis, and the end wire of the pickup. Here is a description (See Step 5) of that process:

http://www.diyguitarmods.com/telecas...structions.php

Hope this helps.

cheers,
Gav.