3-ways and 5-ways - Deaf Eddie

Lever-style Pickup Selectors
The lever-style pup selectors as used by Fender (and others) are actually two-pole
switches. If you look at the STOCK switch, it has two rows of lugs - each row is
considered a pole. So, when you work the lever, you are actually throwing TWO switches
at once.
Look at the first two switches in this drawing (for now, ignore the second two switches):
I've labeled the lugs to reference which position would be selected (Bridge, Middle,
Neck) OR to show that they are the Common lug - that's the unchanging lug that the
other lugs are switched between.
As you work the lever you are moving a wiper, which comes in contact with (or loses
contact with) the three switchable lugs. The common lug is ALWAYS in contact with the
wiper.
A Tele scheme is pretty straight ahead - three throws on the switch, three different tones.
This is achieved by using one pole (one side) of the switch to select the bridge pup, and
the other side of the switch to select the neck pickup. There are actually two ways to do
this - you can have the pups connected to the commons, or the output connected to the
commons...

In this drawing, the pickups are wired to the commons, and the switchable lugs are
jumpered together and on to the output:
You can see that the neck pup is connected to the output in two throws; the bridge pup is
connected in two throws.
NEXT:
Here's a Strat, where they use one pole (one side) to select the pickups, and one pole to
select the tone pots:
On a Strat, the COMMONS are connected and routed to the volume pot. Because the
commons are jumpered together, when the neck pup is selected, the neck tone pot is also
in the circuit. The same goes for the middle pup.
Remember, when this switch was first used, Strats also only had THREE throws, and Leo
used the same switch in Strats and Teles.

SOME HISTORY:
The #2 and #4 throws (where the Strat's "quack" is) came about because players
discovered that because of the way that original 3-way selector was designed ("make
before break" style), if you carefully got the lever to stick in the "in-between" spot. I'm
sure Leo selected this particular switch to eliminate possible "popping" sounds when
switching between pickups. In between the original #1 and #2, (and #2 and #3), the
switch's wiper would actually make contact with the next lug BEFORE it lost contact
with the previous lug - so you heard TWO pickups on your Strat at once!
Some Strat player figured that little trick out, fiddled with the switch until he got it to
play two pups at once, finding the QUACK - and the rest is history. It was a happy
accident, but it was flat amazing!
All they had to do was to add two mechanical "stops" to the 3-way switch, so that it
would stay at the "touching-two-lugs" point in its travel. There's no difference in the lug
layout of the standard 3-way and 5-way, it's just a matter of how we wire them up.
After a third-party began marketing these 5-throw/3-way switches with two extra "stops"
at throws #2 and #4 (as I recall, late sixties, early seventies), Fender finally made the 5-
way selector switch stock on Strats (mid-seventies, if memory serves). The wiring didn't
change, just the switch, and only slightly - two new "notches" were made in the
mechanical action of the switch, so that it would consistently stop while contacting two
of the lugs - so we could all get the magic "in-between" tones.
******
The other two switches in the first drawing are examples of other 5-ways. They still have
two poles, but the poles are in-line and one after the other. Can you see them?

Here's a drawing I’ve done that might enlighten - a side view of a 3-way/5-way:
This is ONE POLE, remember - it's repeated in mirror image on the other side of the
switch. You can see that the common lug is always in contact with the wiper, and the
contact point on the wiper moves across the switchable lugs as you work the lever.
******
You have to fully grasp the concept that your 3-way (or 5-way) is really TWO separatebut-parallel-and-synchronized
switches.
In Strats and Teles, the jumpers between the two poles (wires that cross over) are
simply to connect the results of those TWO separate switches. It is then sent on to
the volume pot.
In the case of the stock Strat, with the two COMMONS jumpered together, it's because
one pole runs the pickup selection, and the other pole runs the tone control selection.
Now, they could have just connected both commons separately to the volume pot - yes,
they could have run two wires meeting at the volume pot, using NO JUMPERS - and
achieved the same thing.
Jumpering them together across the switch is just a "shortcut" to have both the tone-potsside
of the switch and the pickups-side of the switch connected to the volume pot with the
minimum amount of wire.
They don't really HAVE to have any lugs jumpered together, there's no circuitry magic -
it's just a wiring shortcut.

On a Tele, they used BOTH poles for pickup selection - one pole runs the bridge pup, and
one pole runs the neck pup. Adjacent switchable poles are jumpered together because
each of the two Tele pups is "on" in two of the three throws - so you gotta have two lugs
out of three connected for each pup.
The jumper wire that runs across the switch is, again, just a wiring shortcut. They could
have run a separate wire from the bridge side of the switch to the volume pot, and run
another wire from the neck side of the switch to the volume pot - but, hey, since we're all
going to the same place, why not "hook up and share the ride?"
It's not magic, it's not mysterious electronic wizardry, it's just logical wiring shortcuts.
Leo was nothing if not thrifty and efficient!