We have been doing a lot of custom wiring here lately...

like this one for a customer who wanted to copy Robbie Robertson's 1954 Strat
he had dipped in bronze (!) for The Band's "The Last Waltz" show. It's shown on the front page.

His original guitar used a stock three position selector switch, a 1954 Strat rhythm pickup,
a 1957 left handed middle pickup moved next to the lead pickup for a 'humbucker' look, and a 1965 lead pickup.
This gave him two basic modes - a basic Strat mode with the usual rhythm/middle/lead,
and a humbucker mode with the middle and lead together as a humbucker.

I did RR's wiring one better by using a five way selector switch instead of a stock threeway switch
(for parallel humbucker effects), a custom wound 5S4 rhythm pickup with special Alnico III magnets,
a 5S7LH middle pickup wired RW/RP for the humbucker coil, a custom overwound 6S5 lead pickup
powerful enough to keep up with the other two pickups (for volume calibration),
a CTS pull pot for switching in the humbucker modes, and then I split the tone controls
 with a .047 rhythm tone cap and a .022 cap for both middle and lead pickups.

Now, the 'normal Strat' mode has five sounds not three -
5S4 rhythm single coil alone, rhythm and middle as parallel humbucker, middle single coil alone,
middle and lead as parallel humbucker, and lead pickup alone single coil.

The 'RR' mode is something else...

5S4 rhythm single coil alone,
5S4 in parallel with a series humbucker made from 5S7 and 6S5 together
(with all three pickups on at once !)
5S7LH and 6S5 as series humbucker at almost 12K DCR,
5S7LH and 6S5 as parallel humbucker,
and 6S5 lead pickup alone.

Never mind the stats, here are the photos.

This is mounted on a throwaway pickguard I had for shipping purposes
as the custom made pickguard wouldn't arrive in time for shipping.

That pickguard looks like a two pickup guitar, as the middle pickup
 would be pushed next to the lead pickup to look like a humbucker.


The top of the RR Strat pickguard. Notice how everything looks so 'normal' on this side...
The rhythm pickup is a 5S4 with Alnico III magnets, the middle pickup is a 5S7 LH (left handed) pickup mounted upside down,
 and the lead is a custom overwound 6S5 to deal with the volume drops RR had issues with on his own instrument.

The weird side... notice the middle pickup is mounted upside down. This is for clearance purposes as
the custom pickguard will have the middle pickup moved next to the lead pickup like a humbucker.
The finished assembly will look like a two pickup guitar - a rhythm single coil and a humbucker lead

The switching system - all CTS controls, Mallory 150 series tone caps, and a whole lotta caffeine.
After this one, I was glad I went back to college to finish my EE degree

And here is the wiring diagram I used as the original inspiration for this setup.
I'm told it was hand drawn from RR's original wiring.
It doesn't look like much, but the details were what caused all the problems...