In this post are a series of diagrams to show how a blower switch could be wired up in a guitar.
A Blower switch is one that sends the output of the pickup directly to the output jack bypassing the guitars volume and tone controls and any other circuitry.
One use of such a switch would be that another sound using a different volume, tone, and pickup selection is being used and by engaging the blower switch the bridge humbucker, for example, is sent directly to the output jack bypassing the preselected settings on the selector switch, volume, and tone.
For a humbucker using a 4PDT is probably the best way of ensuring isolation between the two different positions and avoiding “bleed”.
The diagrams use Seymour Duncan colour codes, but for other pickups consult the manufacturers colour codes and adjust accordingly. The logic is the same even if the wire colours differ.
First, let’s take a look at a 4PDT switch wired to do the job that we want.
The blue dashed lines show what is described as Switch position A in the diagram. This is the internal connectivity within the switch when in that position.
The purple dashed lines show what is described as Switch position B in the diagram. This is the internal connectivity within the switch when in that position.
Now, lets take a look at the Blower Switch A position. The A position takes the signals from the North and South coils into the guitars selector switch, volume and tone etc or any other switching such as series/parallel switching. The hot wire that is shown in black then leaves the Volume pots centre output to its own pole on the switch which then sends it to the output jack.
Looking at the Blower switch B position, this time the inputs from the pickup are now switched as follows. The black hot wire is linked from its input pole of the switch to the pole used for the output to the jack. The red and white wires poles are also joined so that the North and South coils are in series.
One possible option for a 4PDT switch to use is the Fender S1 Switch. The S1 switch is a 4PDT switch attached to a potentiometer.
The S1 is available in two types for Stratocaster type guitars or Telecaster type and in 250K or 500K values.
Here is the complete wiring.
Here is position A or the switch disengaged.
And here is the S1 wired as a blower switch engaged and bypassing the guitar’s circuitry direct to the output jack.
Hope this is useful…